Question

A can do 50% more work than as B can do in the same time. B alone can do a piece of work in 20 hours. A, with help of B, can finish the same work in how many hours ?

(a) 12 (b) 8 (c) 13 1/ 3  (d) 5 1/2 (e) None of these

Answer 1

(b) B alone can do a work in 20 hours.

A alone can do 3/2 of the work in 20 hours. 

A and B together can finish the whole work in 8 hours.