A can do a piece of work in 16 days and B can do the same work in 20 days. In how many days can they do the same work, working together?

Options

A. `8(1)/(9)`
B. `9(8)/(9)`
C. `8(8)/(9)`
D. `9(1)/(8)`

Answer

C

Explanation

A can do `(1)/(16)`th of the work in one day.
B can do `(1)/(20)`the of the work in one day.
The part of the work done by A and B together
`(1)/(16) + (1)/(20) = (5 + 4)/(80) = (9)/(80).`
`therefore " Both together can complete the work in " (80)/(9) " days, i.e.," 8(8)/(9) " days".`
Hence, the correct option is (c).