Question

3. A boy can do a piece of work in 15 days and his father can do it in 10 days. How long will it take them to do the work together? A. 6 days B. 7 days C. 8 days D. 9 days

Answer 1

How long will it take them to do the work together? A. 6 days

the boy does 1/15 of the work per day

father does 1/10 of the work per day

together they do 1/15+1/10 = (2+3)/30=5/30 =1/6

To know how long it will take them to complete the work together, this fraction must be reversed = 6

it takes 6 days

Explanation: