Question

Ques. A and b can together finish a work 30 days. They worked together for 20 days and then b left. After another 20 days, a finished the remaining work. In how many days a alone can finish the work?

Answer 1

Answer:

The work completed by A&B in one day is,

1/A + 1/B = 1/30 —(1)

(1/A + 1/B) * 20 + 1/A * 20 = 1 —(2)

Substitute the value of equation (1) in equation (2),

20/30 + 20/A = 1

20/A = 10/30

1/A = 1/60

So A alone can finish work in 60 days.