Question

A and B together can do a piece of work in 12 days, while B alone can finish it in 30 days. A alone can finish the work in :
A. 15 days
B. 18 days
C. 20 days
D. 25 days

Answer 1

Answer: 20 Days

Step-by-step explanation:

Let, A and B can do a piece of work in 1/12 days

A can do a piece of work in 1/X days

B can do a piece of work in 1/30 days

So, 1/A + 1/B = 1/AB

1/X + 1/30 = 1/12

Hence, 1/X = 1/20 days

So, X = 20 days