Question

A and B are doing a work

Answer 1

A can do it in = 9 days

B can do it in = 12 days

Work done by A in 1 day = 1/9

Work done by B in 1 day = 1/12

Work done in first 2 days = 1/9 + 1/12 = 7/36

Work done in 10 days = 35/36

Work remaining = 1 - 35/36 = 1/36

Time taken by A to complete the remaining work = 9 * 1/36 = 1/4

So the whole work will be done in 10 + 1/4 = 10 1/4 days