f A alone can do a piece of work in 8 days and B alone can do the same work in 12 days. How many days A and B required to finish the same work if they work togather?

If A alone can do a piece of work in 8 days and B alone can do the same work in 12 days. How many days A and B required to finish the same work if they work togather?

A. 24/5 days
B. 24 days
C. 5day days
D. 5/24 days
E. None of these












 Option A

Explanation:
A alone one day work = 1/8
B alone one day work = 1/12
Both A and B one day work = (1/8 + 1/12) = (3/24 + 2/24)
= 5/24
so A and B together finish the work in 24/5 day 
or 4 4/5 days.