A can do a piece of work in 10 days and B in 15 days. How long will they take together to finish it ?
A’s 1 day work = 1/10
B’s 1 day work = 1/15
(A + B)’S 1 day work = 1/10 + 1/15
= (3 + 2)/30 = 5/30
= 1/6
∴ Both A and B together can finish the work in = 6 days