Question

A can do a piece of work in 4 hours; B and C together can do it in 3 hours, while A and C together can do it in 2 hours. How long will B alone take to do it?

Answer 1

A=4----------(1)
B+C=3------(2)
A+C=2------(3)
Subtract 3 from 2
B-A=1
But A=4(from 1)
.: B=5