Question

A can do a piece of work in 25 days and B can finish it in 20 days. They work together

for 5 days and then A leaves. In how many days will B finish the remaining work?

Answer 1

A can do a piece of work in 25 days

⇒ A can do a work of W/25 in one day

B can do a piece of work in 20 days

⇒ B can do a work of W/20 in one day

given the both work 5 days

5 days work of both A and B is 5W/25 + 5W/20 = W/5 + W/4 = 9W/20

remaining work after A leaves is W - 9W/20 = 11W/20

11W/20 work is to be done B alone and B can do a work of W/20 in one day

⇒ B completes the remaining work in 11 days.

Answer 2

Thank you for asking this question. Here is your answer:

Suppose total work is 1

A=1/15 & B=1/25 for one day work

when both work together

(A+B)= (1/15)+(1/25)=7/60

for 7 days

(7/60)x7=7/15

For remaining work

1-(7/15)=8/15

Answer (8/15)