A and B together can do a piece of work in 40 days. A having worked for 20 days,

Loading

Choose the correct option.

A and B together can do a piece of work in 40 days. A having worked for 20 days, B finishes the remaining work alone in 60 days. In How many days shall B finish the  whole work alone?

2 hours
8 hours
6 hours
4 hours