Question

a and b working separately can do a piece of work in 9 and 12 days a begining in how many days they will be completd

Answer 1

A can complete whole work in = 9 days

B can complete whole work in = 12 days

1 unit work completed by A and B together in 1 day = 1/9 + 1/12

= 4+3/36 = 7/36

So A and B can together complete the work in = 36/7 days = 5 1/7 days