Q: P can do a work in 24 days. Q can do the samework in 9 days & R can do the same work in 12 days. Q & R start the work and leave after 3 days. P finishes the remaining work in how many days.
Options:
(A) 8
(B) 10
(C) 14
(D) 16
(E) 19 Let's give some random thoughts before answering.
Work done by P in 1 day = 1/24
Work done by Q in 1 day = 1/9
Work done by R in 1 day = 1/12
Work done by Q and R in 1 day = 1/9 + 1/12 = 7/36
Work done by Q and R in 3 days = 37/36 = 7/12
Remaining work = 1 7/12 = 5/12
Number of days in which P can finish the remaining work = (5/12) / (1/24) = 10
Therefore, the answer is (B).