A and B together can do a piece of work in 10 days. A alone can do it in 30 days. The time in which B alone can do it is :
(a) 10 days
(b) 12 days
(c) 15 days
(d) 20 days
Correct option (c) 15 days
Explanation:
A + B – A = B’* efficiency
3 – 1 =B’* efficiency
2 = B’* efficiency
B alone does in = 30/2
= 15 days
