P can do a work in 42.5 days. Q can do the same work in 25.5 days and R can do the same in 34 days.

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19 Jan 2018 Time and Work

P can do a work in 42.5 days. Q can do the same work in 25.5 days and R can do the same in 34 days. Q and R start the work and leave after 6 days. P finishes the remaining work in X days. What is the value of X+3?

OPtion

1) 25 days
2) 15 days
3) 28 days
4) 20 days
5) 24 days
6) 18 days
7) 21 days
8) 22 days
9) 23 days
10) None of these

Solution

Amount of work done by Q and R in 6 days = 6*(1/25.5 + 1/34) = 6*((2+1.5)/51) = 21/51 = 7/17
Amount of work remaining after 6 days = 10/17

Amount of work done by P in 1 day = 1/42.5
So for 1/42.5 work P takes 1 day
Hence for 12/17 work P would take (1/(1/42.5))*10/17 = 25 days

X+3 = 28
Option 3)

Correct Option: 3 Best Solution (0)