Question

A alone can do a piece of work in 7 days and B alone can do the same work in 8 days. If both of them work together, how long will they take to complete the work?

3 days
4 days
4.7 days
3.7 days

Answer 1

Answer:

Let B alone take x days to do the work

A and B together in 1 day do 1/12+ 1/x = 1/7.5

1/x = 1/7.5 - 1/12 = 4.5/ 90= = 45/900= 1/20

x = 20 days

B alone = 20 days

C alone = 23 days ANSWER