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Time and Workby Sindhoor Grandh i - T hursd ay, 9 July 2009 , 01:59 PM

When we started TG.Com, we were c lear that TG would write about quant and I aboutbusiness schools (India and Abroad). And who would write about verbal? No clue. Theadmission process, the happenings at business schools, interviews and group discussionsused to excite me more than anything e lse in CAT arena. But as I moved closer to diggingmore information about business schools, I realized that Indian business schools do nothave a very transparent admissions process. As far as learning goes, I started feeling thestagnation. I was not seeing much growth in that area and I did not want to move to theGMAT arena when I had yet not explored the Indian exams to their full potentia l. Back then,my love for language was not at its peak but I thought verbal was where I could be. I donot know when I decided to step into C AT Verbal Forum but I just took the step. As Istarted working in the CAT Verbal Forum, I started connecting with students on bothpersonal and professional level. Today, if I want to count how many thankyous TG and Ihave received in these two years, I think I would fail. From Indian B School Maven, I havebecome TotalGadha.Com's verbal instructor and International B School Maven. It has been

a long journey and I can only smile when I look back today. TotalGadha.Com is slowly becoming everybody 's website . More thananybody else, our students are becoming our strongest support. So far you have seen student contributions in the form of CAT articles,you have seen contributions in our CBT Club , and you have seen contributions in the form of blogs. Today we present you acontribution from our GMAT blog.

Sindhoor has contr ibuted an artic le on 'How to prepare for GMAT Verbal Section' before as well but this time we wanted to give him abigger exposure. TG has really gr inded him in solving loads of questions and he has been continuously working on the article from past

many days. Don't forget to say thank you to him. - Dagny

Problems on T ime and Work are a c ommon feature in most of the standard MBA exams. If you are well versed withthe basics and have practised these problems during your preparation, they give you an easy opportunity to scoreand also save time. Here, I will try and give you the basic fundas with the help of examples. Let us start with a verybasic problem:

Problem 1: A takes 5 days to complete a piece of work and B takes 15 days to c omplete a piece of work. In howmany days can A and B c omplete the work if they work together?

Standard Solution: Let us consider Work to be 1 unit. So if W = 1 Unit and A takes 5 days to complete the workthen in 1 day A completes 1/5th of the work. Similarly B completes 1/15th of the work.If they work together, in one day A and B c an complete (1/5 + 1/15 = 4/15) of the work. So to complete 1 unit ofwork they will take 15/4 days.

New method: Let us assume W = 15 units, which is the LCM of 5 and 15.

Given that total t ime taken for A to c omplete 15 unit s of work = 5 days--> As 1 day work = 15/5 = 3 unitsGiven that total t ime taken for B to c omplete 15 unit s of work = 15 days--> Bs 1 day work = 15/15 = 1 unit-->(A + B)s 1 day work = 3 + 1 = 4 units-->15 units of work can be done in 15/4 days.

Many solve Time and Work problems by assuming work as 1 unit (f irst method) but I feel it is faster to solve theproblems by assuming work to be of multiple unit s (second method). This would be more evident when we solveproblems whic h are litt le more complex than the above one.

Problem 2: X can do a work in 15 days. After working for 3 days he is joined by Y. If they complete the remainingwork in 3 more days, in how many days can Y alone complete the work?

Solution: Assume W = 15 unit s.(Note: You can assume work to be any number of units but it is better to take the LCM of all the numbers involved inthe problem so that you can avoid frac tions)X c an do 15 units of work in 15 days-->X can do 1 unit of work in 1 day

(Note: If I had assumed work as 13 units for example then Xs 1 day work would be 13/15, whic h is a fraction andhence I avoided it by taking work as 15 units which is easily divisible by 15 and 3)Since X worked for 6 days, total work done by X = 6 days 1 unit/day = 6 unit s.Units of work remaining = 15 6 = 9 units.All the remaining units of work have been c ompleted by Y in 3 days-->Ys 1 day work = 9/3 = 3 units.If Y can complete 3 units of work per day then it would take 5 days to complete 15 units of work. So Y takes 5 daysto complete the work.



Problem 3: A, B and C c an do a piece of work in 15 days. After all the three worked for 2 days, A left. B and Cworked for 10 more days and B left. C worked for another 40 days and completed the work. In how many days can Aalone complete the work if C can complete it in 75 days?

Solution: Assume the total work to be 600 units. (LCM of all the numbers)Then Cs 1 day work = 8 unit s.-->(A + B + C)s 1 day work = 40 units.A, B, C work together in the first 2 days-->Work done in the first 2 days = 40 2 = 80 unitsC alone works during the last 40 days-->Work done in the last 40 days = 40 8 = 320 unitsRemaining work = 600 (320 + 80) = 200 unitsThis work is done by B and C in 10 days.-->(B + C)s 1 day work = 20 unit s-->As 1 day work = (A + B + C)s 1 day work (B + C)s 1 day work = 40 units 20 unit s = 20 units-->A can do the work of 600 units in 30 days.

Problem 4: Gerrard can dig a well in 5 hours. He invites Lampard and Rooney who can dig 3/4th as fast as he can tojoin him. He also invites Walcott and Fabregas who can dig only 1/5th as fast as he can (Inefficient gunners you see

) to join him. If the f ive person team digs the same well and they start together, how long will it take for them tofinish the job?

Solution: Let the work be 100 units.Gerrards 1 hour work = 100/5 = 20 unitsLampard and Rooneys 1 day work = 3/4 20 = 15 units.Fabregas and Walcotts 1 day work = 1/5 20 = 4 unit s. In one day all f ive of them can do = 20 + 15 + 15 + 4 + 4 = 58 units of work. Hence they can complete the work in100/58 days.

I hope you got the knack of it. Let us now see how to solve the second kind of problems in Time and Work theMANDAYS problems.

In these kinds of problems we need to remember that the number of men multiplied by the number of days that theytake to complete the work will give the number of mandays required to complete the work. The number of mandaysrequired to c omplete a piece of work will remain constant. We will t ry and understand this concept by applying it tothe next three problems.

A Very simple problem to start with:

Problem 5: If 10 men take 15 days to c omplete a work. In how many days will 25 men complete the work?

Solution: Given that 10 men take 15 days to complete the work. So the number of mandays required to complete thework = 10 15 mandays. So assume W = 150 mandays.

Now the work has to be done by 25 men and since W = 150 mandays, the number of days to c omplete the workwould be 150/25 = 6 days.

Problem 6: A piece of work c an be done by 8 boys in 4 days working 6 hours a day. How many boys are needed tocomplete another work which is three t imes the f irst one in 24 days working 8 hours a day?

Solution: Assume the first piece of work to be 8 4 6 = 192 boy-day-hours.The second piece of work = 3 (The first piece of work) = 3 192 = 576 boy-day-hours. So W = 576 boy-day-hours.If this work has to be completed in 24 days by working 8 hours a day the number of boys required would be 576/(24 8) = 3 boys.

Problem 7: X can do a piece of work in 20 days working 7 hours a day. The work is started by X and on the secondday one man whose capac ity to do the work is twice that of X, joined. On the third day another man whose capacityis thric e that of X, joined and the process cont inues till the work is completed. In how many days will the work becompleted, if everyone works for four hours a day?

Solution: Since X takes 20 days working 7 hours a day to c omplete the work, the number of day-hours required tocomplete this work would be 140 day-hours. Like in the two problems above, this is going to be constant throughout.So, W = 140 day-hours.Amount of work done in the 1st day by X = 1day 4 hours = 4 day-hours2nd day, X does again 4 day-hours of work. The second person is twic e as effic ient as X so he will do 8 day-hours ofwork. Total work done on sec ond day = 8 + 4 = 12 day-hours. Amount of work completed after two days = 12 + 4 =16 day-hours.3rd day, X does 4 day-hours of work. Second Person does 8 day-hours of work. Third person who is thrice aseff icient as X does 12 day-hours of work. Total work done on 3rd day = 4 + 8 + 12 = 24 day-hoursAmount of work completed after 3 days = 16 + 24 = 40 day-hoursSimilarly on 4th day the amount of work done would be 4 + 8 + 12 + 16 = 40 day-hoursWork done on the 5th day = 4 + 8 + 12 + 16 + 20 = 60 day-hoursTotal work done after 5 days = 4 + 12 + 24 + 40 + 60 = 140 day-hours = W.So it takes 5 days to c omplete the work.

Remember that whenever there is money involved in a problem, the money earned should be shared by



people doing the work together in the ratio of total work done by each of them. Again I will explain this withthe help of an example:

Problem 8: X can do a piece of work in 20 days and Y can do the same work in 30 days. They finished the work withthe help of Z in 8 days. If they earned a total of Rs. 5550, then what is the share of Z?

Solution: Let work W = 120 units. (LCM of 20, 30 and 8)Xs 1 day work = 6 unit sYs 1 day work = 4 unit s(X + Y + Z)s 1 day work = 15 units.

So Zs 1 day work = 15 (6 + 4) = 5 unitsIn 8 days Z would have completed 5 units/day 8 days = 40 unit s of workSince Z does 40/120 = 1/3rd of the work, he will receive 1/3rd of the money, which is 1/3 x 5550 = Rs. 1850. Pipes and Cisterns Problem 9: There are three hoses, A, B and C, at tached to a reservoir. A and B can fill the reservoir alone in 20 and30 mins, respectively whereas C c an empty the reservoir alone in 45 mins. The three hoses are kept opened alone forone minute each in the the order A, B and C. The same order is followed subsequently. In how many minutes will thereservoir be full? Solution: These kinds of problems can be solved in the same way as we solve problems where one or more men areinvolved. A, B and C are equivalent to three people t rying to c omplete a piece of work.The amount of work to be done would be the capac ity of the reservoir. Lets assume c apacity of the reservoir = W =180 (LCM of 20, 30, 45) litres.A c an fill the reservoir in 20 mins In 1 min A can fill 180/20 = 9 L. B can fill 180/60 = 6 L in a minute.In one minute C can empty 180/45 = 4 L from the reservoir.

1st Minute => A is opened => fills 9 L

2nd Minute => B is opened =>fills another 6 L

3rd Minute => C is opened => empt ies 4 LHence every 3 minutes => (9 + 6 4 =) 11 litres are filled into the reservoir.So in 45 minutes (11 15 =) 165 litres are filled.

In the 46th minute A is opened and it fills 9 litres. In the 47th minute B is opened and it f ills 6 lit res.Hence the reservoir will be full in 47 minutes.

Problem 10: There is an empty reservoir whose capacity is 30 litres. There is an inlet pipe which fills at 5 L/min andthere is an outlet pipe whic h empties at 4 L/min. Both the pipes function alternately for 1 minute. Assuming that theinlet pipe is the first one to function, how much time will it take for the reservoir to be f illed up to its capacity?

Solution: The work to be done = Capac ity of reservoir = W = 30 litres

1st Minute => inlet pipe opened => 5l filled

2nd minute => inlet pipe closed; outlet pipe opened => 4l emptied

In 2 minutes (5 litres -4 litres =) 1l is f illed into the reservoir.

It takes 2 minutes to f ill 1l => it takes 50 minutes to fill 25 litres into the tank.

In the 51st minute inlet pipe is opened and the tank is filled.

Problem 11: Sohan can work for three hours non-stop but then needs to rest for half an hour. His wife c an work fortwo hours but rests for 15 min after that, while his son c an work for 1 hour before rest ing for half an hour. If a worktakes 50 man-hours to get completed, then approximately how long will it take for the three to complete the same?Assume all of them all equally skilled in their work.

(a) 15 (b) 17 (c) 20 (d) 24

Solution: W = 50 man-hoursSince all of them are equally skilled; in 1 hour they can do 3 man-hours of work if no one is rest ing.

It will take them 50/3 = 16.6 hours to complete the work if they work continuously.

But , since they take breaks the actual amount of time would > 17 hours.Opt ion (a) and (b) are ruled out.Now let us calculate the amount of work done in 20 hours.

Sohan does 3 man-hours in every 3.5 hours (because he takes rest for half an hour on the 4th hour) In 20 hours (3.5 5 + 2.5) Sohan completes => 3 5 + 2.5 = 17.5 man-hours -- -- (1)

His wife completes 2 man-hours every 2.25 hours (because she rests on the 3rd hour)In 20 hours (2.25 8 + 2) she completes => 2 8 + 2 = 18 man-hours. --- - (2)Child completes 1 man-hours every 1.5 hour.

In 20 hours (1.5 13 + 0.5) he c ompletes 1 13 + 0.5 = 13.5 man-hours of work. -- ---- (3)

Adding 1, 2 & 3

In approximately 20 hours 49 man-hours will be c ompleted; so the work can be c ompleted in 20th hour.



Rep ly

Re: Time and Workby Rahul Shinde - Thurs day, 9 July 2009, 04 :42 P M

This art icle is re ally very helpful fo r pre paring Tim e and Work topic .

Hop e to get f ew mo re su ch to pics from the a uthor in future .

Show pa rent | Rep ly

Re: Time and Workby sanje eb pa nda - Thursday, 9 Ju ly 2009, 04:47 PM

Gre at article .Thanks a lot.

If u have more num ber o f que stion s pls post.

Reg ards

San jeeb


Re: Time and Workby vishnu mad havan - Thursda y, 9 July 2009, 05:41 PM

Tha nkuuu soo much Sindhoor.R eally nice article

The concept o f tak ing work a s mul itple units is simpl ifying pro bs to a grt extent.T hankuu

Hop e sme day, we chotta gadha s too will be p rovid ing q uality stu ff like dis to our g adha land.Thnku TG & Dagny Maa mRgrdsVis hnu


Re: Time and Workby shiva m meh ra - Frida y, 10 July 2009 , 11:15 AM

nice articletha nk u so much

pro blem 7 is bit p roble matic...4 or 7 hours a da y work is carried ou t not clea r


Re: Time and Workby Sindhoor Grandh i - Friday, 10 July 2009, 11:28 AM

Tha nks Shivam

and read the last line of problem 7 .. it s ays e veryo ne wo rks for 4 hours a da y.



Vis hnu, I am happy you liked it . .. ho ping to se e you r article somed ay on TG



San jeeb, I am short of g ood q uestions in this top ic to o .. but will try and see if I can post more .. or may be yo u can post any that youencounte r during your p reparation .


Re: Time and Workby Software Engine er - Frida y, 10 July 2009 , 12:54 PM

Gre at Ef fort! Nice Article!

Tha nks- SE


Re: Time and Workby the k iller - Friday, 10 July 2009, 03:47 PM



Aws ome a rticle Sir!!

Tha nks a ton. .Hop e to get s ome m ore a rticles from yo u.

Reg ards,Kil ler


Re: Time and Workby Jay Sampat - Friday, 10 July 2009, 04:44 PM

Tha nks A Lot.

I think that there is a typing mistake in a nswer 4. I t wil l be 100/58 hou rs.


Re: Time and Workby Vivek Nara in - Frida y, 10 July 2009 , 07:04 PM

U rock d ude. The a rticle is very helpful. P lease post in s ome m ore p roble ms, e sp. o n pip es n ciste rns, and those like the last p roble mwhe re a perso n tak es a break while working. ..

Tha nks a ton. .


Re: Time and Workby kat g oel - Frid ay, 10 July 2009, 10 :03 P M

I a gree with Jay . Day in problem 4 should be re place d by hour


Re: Time and Workby ayush roy - Saturday, 11 July 2009, 12:38 AM

grt article d ude,feelin so confid ent nw.jus t rep lace 180/60 wid 180/30 in prb 9,jus t a p rintin mis take.TG sir,e xpectin so me challenging prbs frm u in this topic.

tha nksayush


Re: Time and Workby akash gupta - Saturd ay, 11 July 2009, 01 :28 AM

too good boss ..very helpful


Re: Time and Workby amit khete rpal - Saturday, 11 July 2009, 10:10 AM

nice work bro..can u give us article on tsd,percentages,profit n loss..these article help us lot n save our time. .

sir/mam/se/sindhoor

can u make article on each n every topic..n please post sum quest ions too.. i love studying in this site.. i have learnt many things heremore than my coaching institute.A t the same time iam sad today i got backlog in my 6thsem engineering exams my entire planning is nowshatered.iam not able to understand wat i should do..


Re: Time and Workby Punee t Agg arwal - Sa turda y, 11 July 2009 , 07:30 PM

after th is artice I am feeling lot mo re co nfide nt with time and work.... .thanks a lot


Ads not by th is si te



Re: Time and Workby Tuhin Bane rjee - Saturday, 11 July 2009, 10:22 PM

Hi Sindhoor,

Gre at Article , tha nks a lot. Pers onally I l ike this chapte r a lot, could you p lease put some good quali ty questio ns he re sp ecific to Time &Work?

Reg ards,

Tuh in


Re: Time and Workby Parag Para tkar - Saturday, 11 July 2009, 11:38 PM

Hi Sindhoor,

T hanks for the a rticle.... ..... ..... !!!!!

-Pa rag


Re: Time and Workby joyde ep sa rkar - Sunday, 12 Ju ly 2009, 10:44 AM

here is a pro blem...

A group of workers was put on a job. From the second day onwards, one worker was withdrawn each day. The job was finished whenthe last worker was withdrawn. Had no worker been withdrawn at any s tage, the group would have finished the job in two-third of thetime. How many workers were there in the group?


Re: Time and Workby harshhal b andek ar - Sunda y, 12 July 2009 , 05:56 PM

Dear Sindhoor

Nic e art icle on time & work

But I did not follow your third solution properly. I suppose whenever we take the lCM of the individual's working dayswe do it to c alcualte the total workdone in unit s for ex. in the first problem total workdone is 15unit s.

But in third problem you have taken the LCM 15,10,40 2,75.Just want to know the logic behind it. Also Please clarifywhy you have taken the LCM of above nos when the work done by A,B,C is

A = 2 days

B = 2 days with A,B + 10 days with C = 12 days

C = 2 days with A,B + 10days with B + 40 days all alone = 52 days

Please c larify ...


Re: Time and Workby Sindhoor Grandh i - Monday, 13 July 2009, 12:40 PM

Hi harshhal,

Sorry fo r the late reply ..

In problem 3: Whatever you a ssume Work as; remem ber that you ne ed to divide it with 75 d ays(to fin d C's 1 da y work) and 15 days( tofind A+B+C's 1 day work ). So it is eno ugh to tak e W a s the LCM of 75 and 15 wh ich is 75.

Solve the pro blem with W=75 units and you will g et th e sam e ans wer. You need to tak e a m ental note of what you wo uld b e dividing W withwhi le yo u are solving the problem . Got it? Tell me frankly if you still h ave a doub t ..


Re: joydeepby Kulvi r Singh - Monda y, 13 July 2009 , 12:52 PM

Is the a nswer thre e??





Re: Time and Workby Sindhoor Grandh i - Monday, 13 July 2009, 12:53 PM

Guyz,

Try this prob lem. Its a good one ..


Re: Time and Workby Gaura v Mittal - Mond ay, 13 July 2009, 04 :00 P M

gre at wo rk do ne sindhoo r... hope to se e som e more articles like this from you in fu ture. .. th anks a lot


Re: Time and Workby Kulvi r Singh - Tuesd ay, 14 July 2009, 11 :57 AM

@ Sindho or..Nice article. ..Which problem you are talking abo ut..? ?


Re: Time and Workby Amar Kr Dubedy - Tue sday, 14 July 2009, 03:48 PM

Ans is 6 ??


Re: Time and Workby joyde ep sa rkar - Tue sday, 14 July 2009, 10:43 PM

the answer is 3...


Re: Time and Workby Vickram As okan - Wed nesda y, 15 July 2009 , 10:51 AM

Gre at article ...Kud os... Post more chal lenging problem s on the topic. .

Tha nks,-VI ckram .


Time and Workby Shyam Mana wat - Wednesday, 15 July 2009, 05:08 PM

very nice artical.

i learne d a lot. i try to us e it in ea ch prob.

tha nx


Re: Time and Workby Sindhoor Grandh i - W ednes day, 15 Ju ly 2009, 05:46 PM

Tha nks Kulvir, I was te lling abou t the prob lem p osted by joydee p only and 3 is the right answer


Re: Time and Workby Sindhoor Grandh i - W ednes day, 15 Ju ly 2009, 05:47 PM

Tha nks Shyam


Re: Time and Workby joyde ep sa rkar - Wed nesda y, 15 July 2009 , 06:34 PM

Two frie nds d ecide to work together and com plete the construction of the four walls of a room which is in the sha pe of a sq uare.however,asb fell s ick,a started the wo rk alone a nd co mpleted the con struction of one wal l and took "t" hours more than what they would have tak en ifthe y had work ed to gethe r.after th is a left and b ,work ing a lone completed the constructio n of the s econd wall and took "(25/16)t" hours



more tha n wha t the y wou ld ha ve ta ken i f the y had work ed to gethe r.Fin ally,both of th em wo rked together a nd co mpleted the rem aining twowal ls.th e con struction of th e fou r wal ls wa s com plete d in 121 d ays.

in how m any d ays can b alone comp lete the constructio n of the four walls?

if a total of 3600 is p aid for th e entire work,what is the share of a???


Re: Time and Workby Kulvi r Singh - Thurs day, 16 Ju ly 2009, 12:12 AM

A can ma ke 4 walls in 9 days ...


Re: Time and Workby jyoti verm a - Friday, 17 July 2009, 12:12 AM

hi

Tha nks for th e pos t .

Nice fundas!!


Re: Time and Workby antriksh a garwa l - Friday, 17 July 2009, 04:27 PM

hi joyde ep,

kindly p rovid e a d etailed so lutio n of the a bove problem (wall constructio n pro b) as i am unab le to solve it.

tha nks.

antriksh


Re: Time and Workby kumar swam bhu - Sund ay, 19 July 2009, 10 :16 AM

this art icle have some really tricky q uestions


Re: Time and Workby tarun bhavnani - Sunday, 19 Ju ly 2009, 01:21 PM

an s is ---> b ca n do it in 45 d ays.. ..sol .-->say a ca n do wrk in l d ays a nd b can d o it in m days. ..both can do i t in n days....l-n=t and m-n = (25/16) tand l+m +n = 121*24 (converting da ys to hrs)

3 e quations n 3 unknowns...s olve. .enjoy..


Re: Time and Workby Heman t Ahire - Sunda y, 26 July 2009 , 08:13 PM

X c an do a piece of work in 20 days and Y c an do the same work in 30 days. They finished the work with the help ofZ in 8 days. If they earned a total of Rs. 5550, then what is the share of Z?Ple ase correct me if I m wro ng.

1/20+1/30+1/Z = 1/8

1/Z = 1/8 - (50/600)

1/Z = 1/8 - 1 /12

1/Z = 1/24

The refore Z can do piece of work in 24 days . So the ration of X:Y:Zwill b e 20:30:24 . The refore sha re of Z wi ll be 5550*(12/37) = 1800 .





Re: Time and Workby cc6886 cc - Tue sday, 28 July 2009, 11:39 AM

hi Sindhoor,

won t the ans be true fo r all mult iples of 3 (reg arding the no o f workers problem).. . i think 6,9 would also be right.. .ple ase correct if am wrong.


Re: Time and Workby Umang Mathur - Wedne sday, 29 July 2009, 04:35 PM

The solu tion to la st problem seem s pro blem speci fic. Had the to tal m an-ho urs required to comp lete the work were not 50 but some cree py

number, then direc tly multiplying by a number, as in this case by 20, would no t be easily pos sible , rather, we wo uld have thenuse d, hi t and tria l app roach .

Ple ase C orrect me if I am wrong.

Reg ards Uma ng


Re: Time and Workby dipta deep banerjee - Wednesday, 29 July 2009, 10:22 PM

hi Heman t,

I think we ne ed to cons ider the ratio of wo rk do ne ra ther than the t ime taken in do ing the wo rk.. that's wha t i unders tand.

Can anyo ne te ll me how to so lve joydee p's f irst question p lease ?


Re: Time and Workby Ajayk umar Kamne - Thursda y, 30 July 2009 , 10:21 AM

hey tarun,

I had a doubt in u r solution for the q uestion with 4 walls .

1. as the roo m is a square, the a mount of work reqd to do each of th e wal l wou ld beequal.2. and consid ering l,m,n to be the hou rs ta ken b y a,b and a+b together to build one wall .the equa tions would be,

l-n = tm-n = 25 t/16and l+m+2n = 121*24 (no t l+m +n = 121*24 , 2n because they build two walls toge ther. )

I h ave a doub t in the third equation o f you r solution . Correct me if am wrong.


Re: Time and Workby Ajayk umar Kamne - Thursda y, 30 July 2009 , 10:49 AM

solution for joyde ep's first ques tion,

let n be the no. o f persons working on firs t day, thn

no of pe rsons work ing f irst day = nno of pe rsons work ing s econd day = n-1no of pe rsons work ing third day = n-2hence no of p ersons working on nth day = 1

if all n pers ons k ept working dai ly, thn it took (2/3 )n da ys.

n + n-1 + n-2 + .. ..... . +1 = (2/3)*nusing sum of arithmetic prog ressions a nd so lving this

1/2 [2*(a )+(N-1)(d) ] = 2N/31/2 [2*(1 )+(n-1)(1) ] = 2n/31/2 [n+1] = 2n/3n+1 = 4n /3hence n = 3

and no, n cannot b e any multiple of 3 as ca n be seen here,let x be 1,2,3.... . anythingthe n our equa tion would beco me,xn + xn-1 + x n-2 +.....+1 = (2/3)*xn a nd so lving simi larly1/2 [2*(a )+(N-1)(d) ] = 2N/3, here N = x n1/2 [2*(1 )+(xn -1)(1 )] = 2(xn)/31/2 [xn+1] = 2xn/3xn+1 = 4xn/3xn = 3.n = 3/x (not an in teger)Hence n can o nly take value 3

other wa ys of solving this p roble m are welcome.. .


Re: Time and Work



by brije sh ja dav - Mond ay, 3 August 2009, 12:18 PM

Gre at wo rk and an equal ly great m ethod ... thnk u


Re: Time and Workby manis h kak ati - Tues day, 4 Aug ust 2009, 06:23 PM

I g etting the concepts. ..but some more prob lems will strengthen our basics and acum en...

PLEASE P ROVIDE MOR E PRO Bs ON IT.


Re: Time and Workby harsh Rana - Friday, 7 August 2009, 12:10 AM

Wow..... .Awe- inspiring expla natio n abo ut Time and Work Top ic. As usual sa me like other covere d top ics o n this site. I feel amaze dwhe never i re ad yo ur to pics here and you guys ma ke me addicted of yo ur ma rvellous s ite. This site really educate me fo r my MBAformulations. Just, a week b efore got to know ab out T athaGat and now it'l l become m y diu rnal habbi t of surfing on this webs ite. Infact, ialready send you a 1600 /- cheque for C AT CBT mem bersh ip and num ber s ystem or g eometry e-book. Hope you will respo nd ASAP.

Here, i want to share s ome o f my opinion ab out your s ite. First of a ll, i f you can put a chat box here so as piran ts ca n eas ily intera ct witheach other and dis cuss all there problem also. And, i thin k you guys are fanta bulou s so don't restrict or co nfine yourself with Manag ementexa ms on ly. P rovid e new courses a lso b ecaus e our society e xtrem ely required yo ur kinf of f men tors.

Whe n i read your a rticle abo ut be coming tea cher, i wa s fil led with comple te em otion s because in th is fa st-pa ced country eve ryone run likerat and want to win the race . The y all beco me so much self -inte reste d and caug ht in this mone tary-syste m.

In my po int o f vie w, Te achers and Sold iers are two field which are comple tely negle cted by ou r you th.

I g uess, enough fo r tod ay ke ep po st like th is wh ich a rousing or hold ing the attention of peop le like me .

You guyz are so "O BAMA

Che ers


Re: Time and Workby Prime Optimus - Wednesday, 12 Augus t 2009, 12 :11 AM

Hi,

I had p re-co nceived no tion that Time and work is ted ious. . but this article has ma de it simp ler a nd lu cid..

Tha nks-Ha ri


Re: Time and Workby punit bada l - W ednes day, 12 August 2009, 03:16 PM

Hi,

cou ld yo u put some prob ems which involve pe rsons with diff erent capa bilit ies.. .


Re: Time and Workby Nikhi l Lingala - Thu rsday, 13 Augus t 2009, 10 :00 P M

Tha t was awes ome!! Explained beau tiful ly!!

Tha nks s o much for the post Sindhoor.

Nik hil


Re: Time and Workby PAVAN C - Saturday, 15 August 2009, 08:14 PM

Tha nk yo u very much for this article.

Reg ard,pavan





Re: Time and Workby manis h kak ati - Wednesday, 19 Augus t 2009, 11 :23 AM

Ple ase this f or me :

Theres a lot of work in preparing a birthday dinner. Even after the turkey is in the

oven, theres still the potatoes and gravy, yams, salad, and cranberries, not to

mention setting the table.

Three friends, Asit, Arnold, and Afzal, work together to get all of these chores done.

The time it takes them to do the work together is six hours less than Asit would have

taken working alone, one hour less than Arnold would have taken alone, and half the

time Afzal would have taken working alone.

How long did it take them to do these chores working together?

1. 20 minutes 2. 30 minutes 3. 40 minutes 4. 50 minutes


Re: Time and Workby kanwa rjit chadha - W ednes day, 19 August 2009, 09:14 PM

Bos s,ans is 40 min

but this can be ob taine d by back calcu latio n fro m given an s onlyis there a be tter way to solve???


Re: Time and Workby abhis hek tripathi - Frida y, 21 August 2009, 02:27 AM

tha nk u tg si r for dis article lo king forwa rds 4 more of u r nob le wo rk.ha ve a great day ahead chee rs ab hishe k


Re: Time and Workby Ravi Babu Gudip udi - Frid ay, 21 Aug ust 2009, 03:16 PM

Hi TG,

Tha nk yo u, this a rtica l is really goo d ...


Re: Time and Workby Netra Mehta - Saturd ay, 22 Aug ust 2009, 02:56 AM

" n + n-1 + n -2 + ..... ... +1 = (2/3)*n "I d int g et th is step in the solution to joydeep'sque stion ..Can u ex plain me why u equated these two te rms??


Re: Time and Workby mites h ana nd - Monda y, 31 August 2009, 01:07 AM

hi everyone,the ans for joydee p's 2nd prob wud be- -b can co mplete in 45*4=180 d ays(o nly I thin k u m ight hav m istak en in writ ing h rs in stead of d ayz a t sum places)a-1 /36,b -1/45so a's s hare- (5/9)*3600=2000


Re: ajaykumar kamneby mites h ana nd - Monda y, 31 August 2009, 01:22 AM

frnd...I hop ki I will simpl ify u r sol litt le bi t..let work done by e ach p rson on ea ch da y=1 unitno. of p rsons work ing o n 1st day=n--wo rkdone->n unitsno. of p rsons work ing o n 2nd day=n-1--workd one->n-1 unitsno. of p rsons work ing o n nth day=1--wo rkdone->1 unit



equation beco mes-> n + n-1 + n-2 + .. ... +1=(2/3)[n+n+n.. .upto 'n' times ]

[n(n+1)] /2=(2 /3)n^2

4n^2=3n^2+3n

n^2=3n

n=0 or 3dis carding 0,ans wud b 3 men .


Re: Time and Workby Etti R - Saturd ay, 5 September 2009 , 01:20 AM

Wonderfu l! a very good varie ty... .plea se po st so me mo re su ch problem s...thanks a lo t!!


Re: Time and Workby Priye sh Tungare - Sa turda y, 5 Septe mber 2009, 09:44 PM

hii i...

can anyo ne ex plain me the problem s whe re two or more people are included and they work o n alternate days??i a m not able to s olve this kind of problem s.. p lease help me.. .


Re: Time and Workby nitin bhat - Sa turda y, 5 Septe mber 2009, 11:01 PM

Hi Pr iyesh,

Problems that include 2 or more people can be solved in the similar fashion as you take the units of work.

Ex. A can finish a work in 10 days and B takes 15 days to complete the same work whereas C takes 25 days to do the same job . Find the number of days it takes to finish the

job when:

a) A,B & C all wor k on alter nate days

b)A&B work on the same day and C works the next day.

Soln.Let the total amount of work be 150 units(LCM of 10,15,25) then the respective units of works of A-15,B -10 and C-6.

a)Work completed 1st Day-15(Only A wor ks) 2nd day-10(Only B wor ks) 3rd day -6 (Only C works) so at the end of 3 days the amount of work finished-15+10+6=31Units.hence

they would take Approx.15 days(14.51) to complete the work.

b)When A&B work same day the work comp leted -25 units on day 1 next day since only C works, units of wor k completed on day 2 is 6Units. So at the end of 2 days the unit of

wor k completed is(25+6)=31Units. So to comp lete 150 units it'll take them Appr ox. 10 Days(9.61).

I hope you have understood by now....

Regards,

Nit in Bhat

nit inr.bhat@gmail. com


Re: Time and Workby Priye sh Tungare - Sa turda y, 5 Septe mber 2009, 11:19 PM

hey nitin...it may feel l ike s tupid ity.. .

but can u exp lain one thing. . total un its o f work is 31 .. . the n how did u fin d tha t the y wud take 15 d ays to com plete the work???


Re: Time and Workby nitin bhat - Sunday, 6 Se ptemb er 2009, 12:49 AM

Priyesh,

3Da ys-31 Units of work done, next 3 da ys 62 uni ts do ne, next 3 days 93 units done. ... s o on and s o forth by the end o f 15 days 155 unitsof work will be co mpleted... our targe t is to co mplete 150 units of work. ... s o it' ll be litt le le ss than 15 days ...

Reg ards,Nit in


Re: Time and Workby sindhuja m oramp alli - Friday, 11 Se ptemb er 2009, 04:05PM

rea lly a grea t work

tha nk u so much si r



kee p upd ating thes e kind of works


Re: Time and Workby Neete ndra Mishra - Sunday, 13 Septe mber 2009, 08:51 PM

gud work ...


Re: Time and Workby ramkrishna roy - Thu rsday, 17 Septe mber 2009, 03:54 PM

for exam ple-3 . , h ow are we getting LC M to be 600?????


Re: Time and Workby PAVAN C - Tuesd ay, 22 Sep tembe r 2009, 12 :31 AM

Dea r ram krishna ro y,

The values in the problem are 15,2,10,40,75 so LCM ( 15,2,10,40 ,75 ) =600 .

Reg ards,Pavan.


Re: Time and Workby deves h bha ttacharya - Friday, 25 Se ptemb er 2009, 07:06 PM

I tried the a pproa ch its wonderfu l.

i tried a few more ques tions of d ifferent variety and placing them here

Q1>

if 20 me n or 24 wo men o r 40 boys can d o a work in 12 days working fo r 8 hours a day, How many men working with 6 women and 2 boystak e to do a job 4 time s larger, if th ey wo rk 5 hours a da y for 12 d ay?

STO P HER E first try it do by yourself.if u can 't so lutio n is here.

Solution :tak e lcm as 480.total wo rk ho urs for 1s t job is 12*8= 96 ma n hou rs.now every gro up he re ta kes 96 man hours, so ,first group o f men will do 480/96 = 5 units of work p er ho ur.Sam e is true for g roup of wo men a nd bo ys.

each man will do 5 /20 unit work p er ho ur.each Wom en do 5/24 unit work per hour,each boy will do 5 /40 unit p er ho ur.

now the new task is 4 t imes bigge r i.e 480*4 uni ts.

now equa telet no. of me n working on ne w tas k be = xno. of women working are 6no. of b oys working = 2

now x*(5 /20)+ 6*(5 /24) + 2*(5/40) = 480 * 4

it gives x = 122which is the no of men required.

enjoy


Re: Time and Workby jaya dulan i - T hursd ay, 1 Octo ber 2009, 03:32 PM

Awe some article !!!!

U've mad e tim e & work p robs much easie r and inte resting fo r me. .

Tha nks a ton!!!

@Ta run- hey tarun, i ag ree with Ajay..shudn 't th at be 2n, as bo th of them cons tructed two wal ls to gethe r. Mo reove r, aren't there 4unk nowns and 3 equation s? Plz lea d me to the correct solution. Thanx ..





Re: Time and Workby arpita bansal - Satu rday, 3 October 2009 , 10:27 AM

can some one p lease help me in solving this question:

a large tank of he ight 10m is fitted with a n inlet wh ich can fi ll it in 60 minutes. the tank has 3 outlet pipes f itted at the he ights of 5m, 8m ,9.5m, from the bottom. all the pipes a re op ened simultaneo usly, with the tank being empty ini tially. in how much time 95% o f the tankcan be f illed ? if the o utlert pip e can empty hal f of the tank in 1 a nd ha lf ho urs, the outle t pip e in the m iddle can empty 20% of th e tank in1 h r 12 min a nd ou tlet pipe at th e top can empty 5% o f teh tank in 18 min s


Re: Time and Workby arnab das - Tue sday, 6 October 2009 , 01:32 PM

it' s very helpful. Thanks a lot.

It will be ve ry go od if you can k indly can uploa d an article ba sed o n tim e and distance(Mainly circle p roble m, A,B, C running and how manytim es they me et, k inna. ..... ..)

It will be ve ry he lpful if you do so.. ...


Re: Time and Workby supriya na idu - Thursday, 8 October 2009 , 12:34 PM

Hi

Tha nks for the in forma tion. I have found one site sna pwiz.co.in the re is lot of go od stuff regard ing this chapte r in case if yo u are planningto prepa re as a whole for CAT i strongly recomm end you to look snap wiz .Take the tests there and compa re yo ur pe rcentile s core withres pective to each subject. Now a days there is promo tiona l off er go ing o n.i registered through promotional code SW100CAT you can also try this


Re: Time and Workby Prudhvi G - Thu rsday, 8 O ctobe r 2009, 04 :38 P M

Q1> by DeveshIf 20 me n or 24 wo men o r 40 boys can d o a work in 12 days working fo r 8 hours a day, How many men working with 6 women and 2 boystak e to do a job 4 time s larger, if th ey wo rk 5 hours a da y for 12 d ay?

Alternate solution for this problem:

Work = 12 D X 8 H = 96 Day-HoursAs a gro up of 20 Men or 24 Women or 40 Boys can do the wo rk in same time 20 M = 24 W = 40 B

5 M = 6 W = 10 B (ple ase d o not blam e me for g ender bias - ))

Work = 12 x 8 x 20 man -day-hoursNew work = 4 x pre vious work = 4 x (12 x 8 x 20 ) M-D-HLet the new work b e done by Men a lone. New work done by: 6 W + 2 B + a M => 5 M + 1M + a M ( relation b tw M,W,B )New work = 4 x (12 x 8 x 20 ) = (5+1+a ) x 5 x12a = 128 - 6 = 122 men ~Cheers~Raj


Re: Time and Workby sushi l krishna - Saturday, 10 Octob er 2009, 03:09AM

tha nx


Re: Time and Workby manis h majumder - Mo nday, 12 O ctobe r 2009, 07 :07 P M

it was really a ve ry us eful post for t ime a nd wo rk prepara tion.


Re: Time and Workby VENU REDDY - We dnesd ay, 21 October 2009, 11:24 AM

Tim e and work articles is re ally good. Thank you very much for posting the article here


Re: Time and Workby Panka j Kum ar - Thurs day, 29 October 2009 , 01:02 PM



gre at n summa rized piece on Time and W ork, TG ca n you plea se he lp us on logari thms topic too.

Tha nks!!


Re: Time and Workby smrit i chhabra - Wed nesda y, 4 Novem ber 2009, 10:53 AM

hi! ds a rticle s really help ful! plz g ve su ch article s n a ll im porta nt to pics n CAT ! but i ve sme doubts in problem 9 ve understood upto d tlevet dt 11 l itres are fille d into d reservior a fter dt la st 2 steps plz make me understand n prob lem 3 too!


Time and Work e bookby prate ek ba nsal - Tue sday, 10 Novemb er 2009, 02:15 AM

tg sir

i h ave s ent u cheq ue fo r TSD and geome try e book bt have s tioll nt received .C AT is v ery nea r.pls help

pra teek


Re: Time and Work e bookby jatin arora - T uesda y, 10 Nove mber 2009, 12:50 PM

Dea r Sir ,

the prob lems can a lso b e solved u sing work efficience s als o

1. A doe s work in 5 days so A eff% = 100/5

B do es wo rk in 15 d ays s o B e ff% = 100/15

Eff% of A + Ef f% of B = 100/5 + 100/15 = 400 /15

Both can A and B ca n do work in = 100/400/15

= 15/4 answer

2. A doe s work in 15 da ys so A ef f% = 100/15=20/3

A works for 6 days

so work comple ted b y A in 6 d ays = (20/3)*6 = 40%

so wo rk to be comple ted b y B in 3 d ays = 60%

B eff% = 60/3 = 20%

So B alo ne ca n do work in = 100/20

= 5 days answer


Re: Time and Workby Samit Katiyar - Mond ay, 16 November 2009 , 09:34 PM

Hel lo Sir...

Many many tha nks to u.. ..... ..... In Quant,T ime a nd Wo rk wa s the only section where I have solved a ny questio n correctly.... ..... .But aftergoing th rough ur s olving sk ills. ..... ...I can s olve TnW q uestions.. ..... .....Thank s a lot fo r this gre at tu toria l.... ..... .


Re: Time and Workby Ankit Garg - Tuesday, 24 Novem ber 2009, 11:12 AM

gre at article ... after read ing i real ized how s imple it will b e with tak ing LCM .. . tha nks a lot guys


Re: Time and Workby nidhi soni - Sunday, 29 Novemb er 2009, 05:27 PM

thnx sindhoor awe some artical


Re: Time and Workby abhis hek rai - Tuesd ay, 8 June 2010 , 04:31 AM

I m ay be an idiot, but pleas e see the follo wing.



A g roup of me n decided to do a jo b in 8 days. Bu t sin ce 10 men dropp ed everyda y, th e job got completed in 12 days . How many men wereat the b eginn ing?

I g ot th e ans wer a s 330 . Am I correct. I th ink the an swer, give n as 165 is wro ng..Help!!!


Re: Time and Workby Gul Gul - Tuesd ay, 8 June 2010 , 08:58 AM

Abh ishek ,

The equa tion would be s th like th is:

8x = 12x - 10 (1+2+...11 )

x= 165


Re: Time and Workby abhis hek rai - Tuesd ay, 8 June 2010 , 01:49 PM

Thnx Gulab...

But accroindg ly, 660 me n dro pped in 12 days , but only 165 men were a t the begining!!!!! Shouldn't the no. of drop ped p eople be 110.

The n,

8x=(x-110)*12or, 8x = 12*110-12xor, 4x=12*110or x= 330.

Now plz expla in!!!

als o, in itial ly, the no . of manda ys re quire d 1320, if 165 is th e ans wer a nd af ter a fter dropp ing o f 110 peop le, i t becomes 540. Somethingfis hy!


Re: Time and Workby miti chakraborty - T uesda y, 8 June 2010, 02:29 PM

aja y,

i u sed s imple tria l nd error method 2 solve dis q...

here, t1 /t2= 1/(2/3) = 3/2

the refore, w1 /w2= 2/3

nw capacity o f each person is sam e. Le t us assum e cap acity is x for all.

nw using tria l nd error....

w1= 3x+2x+x=6x

w2= 3x+3x+3x = 9x

w1/w2=2/3

i k nw, i t can t b d prop er wa y 2 s olve ds q. ..but it's time saving...


Re: Time and Workby miti chakraborty - T uesda y, 8 June 2010, 02:56 PM

abh isek,

the no. of me n dro pped during the process is :-

o for th e 1st day

10 for the (2nd, 3 rd, 4 th, 5 th, . ..... .., 12th d ay)

i.e . in total (10 X11)= 110 men were d roppe d according to the q

am i rig ht, g ulab????


Re: Time and Workby Gul Gul - Tuesd ay, 8 June 2010 , 08:53 PM

Yup Miti , u r correct


Re: Time and Workby umang shas tri - Thursday, 2 Se ptemb er 2010, 03:14PM



pre fect


Re: Time and Workby Mohit Sharma - Tuesd ay, 3 Apri l 2012, 09 :58 AM

@ joydee p,Let both the frnd can comple te the wrk in X hrs,the n, fi rst f rnd can co mplete wrk in= X+t h rssecond f rnd can co mplete wrk in= X+25t/16,

We also knw that,1/X=1/(X+t)+1/(X+25t/16 )fro m this we get,4X=5tNow use,(X+t)+(X+25t/16)+2X= 121*24 hrsand calculate the value of X and t.


Re: Time and Workby Mohit Sharma - Thurs day, 5 April 2012, 10:27 PM

Hi Kamal Sir,Ple ase help m e with the ques tion.

Que s: Mini and Vinay are quiz mas ters prepa ring for a quiz . In x minutes, Mini make s y q uestions m ore than Vinay. If i t were pos sible tored uce the time ne eded by ea ch to make a questio n by two m inute s, th en in x minutes Mini would mak e 2y questions more than Vinay.How many ques tions does Mini make in x minu tes?a) 1/4[2 (x+y)-sqrt(2x^2+4y^2)]b) 1/4[2 (x-y) -sqrt(2x^2+4y^2)]c) Eithe r a o r bd) 1/4[2 (x-y) -sqrt(2x^2-4y^2)]e) None of th ese


Re: Time and Workby Mohit Sharma - Wedne sday, 18 April 2012, 06:52 PM

hi Kamal Sir, Ple ase help m e with the above que stion .


Re: Time and Workby Kirti Saho o - W ednes day, 6 June 2012, 10 :31 AM

Hel lo TG,I think there 's a bit o f an anoma ly in the solution for Problem 4.In the s olution it 's given that Lapmpa rd and Roo ney's 1 da y work = 15 uni ts bu t i think it should be 1 hours work and same with Fabre gasand Walcott.So there comb ined 1 hou rs wo rk should be 39 units and thus they can complete the wo rk in 100/39 ho urs o r 2.56 hrs

As per the so lutio n pro vided here the answe r 100 /58 d ays is abs urd b ecaus e tha t's a pprox . 1.72 which is grea ter than 1 day which can' t bethe case as Gerrard him self takes 5 ho urs to com plete the work so with the help of 4 other pe ople he should be ab le to comp lete the workin less time.

Ple ase check the s olution and correct me if i'm wrong .

Tha nks.


Re: Time and Workby kirti vard han - Sund ay, 29 July 2012, 04 :39 P M

my first post on T G:

The re is another concep t tha t can be u sed to solve time wo rk problem s and that is the FR ACTIO N RULE. I will post a que stion here .i wi llgive you the easy metho d.

25 men a nd 20 days to construct a 10 m t wal l.how many men are required to make an 8 mt wall i f it is planned that the work be co mpletedin 10 da ys..

FRACTION RULE:tak e the value of the q uanti ty that is to b e calculated as refe rence ..here 25.

the n fra me the fra ction s by the following:

if numbe r of days decre ases (20 to 10) the numbe r men has to in clrea se so the fraction that has to be m ultip lied should be gre ater than 1 so 20/10 .

nex t for cons tructin an 8 mt wall less er number of me n are requ ired as co mpare d to a 10m t wal l so the f raction ha s to be le ss than 1 i.e.8/10

so men required = 25*(20/10)*(8/10)= 40 men (answer)

hop e this helps u to crack q uestions faster.


Re: Time and Workby Pratibha B - Friday, 3 August 2012, 11:17 AM



Sindhoor,

I have a confusion in problem No.7.

The question says "everyone works for four hours a day". I don' t understand why, then, other workers apartfrom X work more than four hours a day[as per the solution].

Please clarify.Show pa rent | Rep ly

Re: Time and Workby Rhythm Goyal - Sunda y, 5 Augus t 2012, 10 :57 P M

HI Heman t,

Z a lone "can do" work in 24 days. But he wo rked only 8 days.

Als o payment does not d epend on number of d ays worked for, but on the amo unt o f work.

Thus in 8 days he worke d 1/24*8 p art o f work i.e . 1/3 of work.thus p aymen t too 1/3rd only.


Re: Time and Workby samee r sap re - Sunda y, 5 Augus t 2012, 11 :17 P M

tha nk yo u sir..... !!

gr8 and lauda ble work. thank s a lot... ..... !!


Re: Time and Workby Ashwa ni Ku shwaha - Friday, 24 Augus t 2012, 03 :23 P M

cud anyo ne ou t here pro vide me the lin k to the R atio and p roportion forum . I can't find it. I t wou ld be of g reat help. thanx


Re: Time and Workby anil mosal i - Monday, 10 Septe mber 2012, 07:43 AM

u r genius bo ss. Actual ly sp eaking u r tota l n we are gadhas.. thats our site. help us improve sti ll mo re with co ncepts of deepe r

com plexi ty..


Re: Time and Workby jyots na chauhan - Mo nday, 22 O ctobe r 2012, 09 :00 P M

hel lo Sindhoo r, Please solve this ques tion for m e . T hank you.Fou r pip es ca n fil l a reservoir in 15, 20,30 and 60 hou rs re spectively. The firs tone was opene d at 6 AM, seco nd at 7AM, third at 8 AM and the fo urth at 9AM. When will the reservoir be fi lled ?


Re: Time and Workby vivek 231 - Tue sday, 23 O ctobe r 2012, 04 :27 P M

hi

let the capacity o f tank be 60 (l .c.m of 15 ,20,30,60)

and the pipe A wil l fil l at a rate 4 l itres per hour

B a t 3,c at 2 AND D AT 2,

in the f irst hour only A is opene d so 4litrs wil l be fille d

in the s econd A and B s o 7

in the third hour a,b,a nd c 9

in the fourth a,b,cand D 10

now 30 l itres will be f illed at 10a.m after that it will take3 hours to fi ll (30/(4+3+2+1)=3ho urs) ,

so it wi ll be filled co mpletely a t 12.00


Re: Time and Workby ankit SAHAY - Sunday, 8 Septem ber 2013, 10:18 PM



hi,can some one pleas e solve th is questio n:

The rate s at which Alok and Bhask ar wo rk are in the ratio 5 : 4 . The y work on alternate days to co mplete a job. Bhaska r sta rted the job andhe worke d on the last d ay. T he jo b was comp leted in 1 day more than the t ime that Alok a lone would take to comple te it. Find the timetak en (in days) by them work ing together to comp lete the job.


Re: Time and Workby debad itya khan - Monday, 9 Sep tembe r 2013, 01 :43 P M

Eff icien cy of A: B= 5:4let tota l work is 100xtotal wo k=(5+4)x=9xnow tota l work=9x*11=99x( in 22 d ays)in 23 da ys the res t work i,e . x will b e com plete d by B @(x /4x)

the refore total wo rk wi ll be comp leted in 23 days.


Re: Time and Workby ankit SAHAY - Monday, 9 Septem ber 2013, 07:31 PM

tha nx fo r the resp onse but a ns is give n as 40/9 days.


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