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Working alone, three persons, P, Q and R can do a certain job
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27 Aug 2018, 04:04
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88% (01:07) correct 12% (01:07) wrong based on 82 sessions
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Working alone, three persons P, Q, and R can do a certain job in 10, 12, and 15 hours respectively. What is the ratio of the maximum and minimum time taken to complete the job, if at every hour, at least 1 person must work? A. 1:3 B. 1:2 C. 1:1 D. 3:1 E. 15:4 To read all our articles: Must read articles to reach Q51
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Working alone, three persons, P, Q and R can do a certain job
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Updated on: 27 Aug 2018, 04:24
Let total Work unit be 60 So, P will do 6 unit/Hr (As total time taken to complete work is 10 Hrs: 10*6 unit=60) Similarly, Q = 5 Units/Hr & R = 4 Units/Hr For Min Time all three should work Together Together P,Q & R will do =6+5+4 Unit=15 units/Hr Therefore Min. Time taken= 60/15= 4 Hrs
Similarly for max time only one of them work (the slowest one) i.e R Therefore, Max time taken=60/4=15 Hrs.
Req. Ratio=15:4 (Ans E)
Originally posted by MayankSingh on 27 Aug 2018, 04:22.
Last edited by MayankSingh on 27 Aug 2018, 04:24, edited 1 time in total.



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Re: Working alone, three persons, P, Q and R can do a certain job
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27 Aug 2018, 04:23
EgmatQuantExpert wrote: Working alone, three persons P, Q, and R can do a certain job in 10, 12, and 15 hours respectively. What is the ratio of the maximum and minimum time taken to complete the job, if at every hour, at least 1 person must work? A. 1:3 B. 1:2 C. 1:1 D. 3:1 E. 15:4 To read all our articles: Must read articles to reach Q51Three people are working to complete a job, then the shortest time taken to complete if at least 1 person is working then the shortest time is when all the 3 are working together which gives us 4 hours. Now the longest time would be when the person with the longest time is working alone ie 15 hours. Therefore the ratio is 15:4.



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Re: Working alone, three persons, P, Q and R can do a certain job
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27 Aug 2018, 05:33
EgmatQuantExpert wrote: Working alone, three persons P, Q, and R can do a certain job in 10, 12, and 15 hours respectively. What is the ratio of the maximum and minimum time taken to complete the job, if at every hour, at least 1 person must work? A. 1:3 B. 1:2 C. 1:1 D. 3:1 E. 15:4 To read all our articles: Must read articles to reach Q51Max time to minimum time means numerator is bigger than denominator. Eliminate A, B, C Together they can finish the work in 4 hours ( add to their rates). This is minimum time. Maximum time taken is   > when the guy with least efficiency works =15 hours Answer is E Thank you = Kudos
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Re: Working alone, three persons, P, Q and R can do a certain job
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28 Aug 2018, 05:30
if all of them work together they will take 4 hrs that is the minimum time taken. and if the guy who take maximum time work alone that is maximum time taken that is 15 max:min is 15:4 ans E



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Re: Working alone, three persons, P, Q and R can do a certain job
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28 Aug 2018, 05:40
EgmatQuantExpert wrote: Working alone, three persons P, Q, and R can do a certain job in 10, 12, and 15 hours respectively. What is the ratio of the maximum and minimum time taken to complete the job, if at every hour, at least 1 person must work? A. 1:3 B. 1:2 C. 1:1 D. 3:1 E. 15:4 To read all our articles: Must read articles to reach Q51time taken will be minimum when all three will work simultaneously = 1/10 + 1/15 + 1/12 = (6+4+5)/60 = 15/60 = 4 hours time taken will be maximum when R will work alone = 15 hours max / min = 15/4



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Re: Working alone, three persons, P, Q and R can do a certain job
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28 Aug 2018, 07:49
This is a simple but good question. Thanks EgmatQuantExpert




Re: Working alone, three persons, P, Q and R can do a certain job &nbs
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28 Aug 2018, 07:49






