Pipe & Work Question Answers

Work and Time - Quant/Math - CAT 2008

Question 4 the day: June 19, 2002
The question for the day is from the topic - Work and Time.

Shyam can do a job in 20 days, Ram in 30 days and Singhal in 60 days. If Shyam is helped by Ram and Singhal every 3^rd day, how long will it take for them to complete the job?

(1)

12 days

(2)

16 days

(3)

15 days

(4)

10 days

Correct Answer - (3)

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Solution:

As Shyam is helped by Ram and Singhal every third day, Shyam works for 3 days while Ram and Singhal work for 1 day in every 3 days.

Therefore, the amount of work done in 3 days by Shyam, Ram and Singhal = 3/20  +  1/30  +  1/60  =  9+2+1/60 =  12/60  =1/5 th of the job. Hence, it will take them 5 times the amount of time = 3*5 = 15 days.