Can Do Piece Of Work In 10 Days And B In 15 Days

A can do a piece of work in 10 days and B in 15 days. How long will they take together to finish it ?

Answers:

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