Question

A alone can do a piece of work in 12 days and B alone can do the same work in 15 days. They start working together. After 4 days B leaves the work. In how many days will A alone complete the remaining work.

Answer 1

Answer:

It will take 8 and a half day for "A" to complete the remaining work If "B" leaves after 4 days.

Step-by-step explanation:

Suppose Both "A" and "B" takes 12 days to complete the same work.

Now if they start to work together, they will be able to complete it in 6 days. But since B takes 15 days It will be 7 and a half day for them to complete the work. Because 12/2 = 6 and 3/2 = 1.5 Therefore, 6 + 1.5 = 7.5

Now If "B" leaves after 4 days, then they have already done the 4 days work which is 3.5

"A" is alone now and takes 12 days to complete the work. But "B" has helped him therefore it will reduction of 3.5 days for him i.e 12 - 3.5 = 8.5