Question

A and B together finish a work in 30 days .They worked on it for 20 days and then B left. The remaining work was done by A alone in 20 days. A alone can finish a work in how many days?

Answer 1

A+B= 20/30

so work done by A and B. is 2/3

now remaining work is 1/3

1/3 work is completed by A in 20 days

so A alone will complete the work in 60 days