Question

A and b can together do a work in 30. they worked for 20 days then b left the remaing work was done by a in 20 more days

Answer 1

(A+B)'s 20 day's work= ( 1/30× 20) = 2/3

Remaining work = (1- 2/3 )= 1/3

1/3 work is done by A in 20 days

Therefore the whole work will be done by A in = 20×3 = 60 days.