Arithmetic Aptitude :: Time and Work
4. A can do a work in 10 days and B can do the same work in 15 days. So how many days they will take to finish the same work ?
First find the 1 day work of both (A & B)
A 1 day's work = 1/10
B 1 day's work = 1/15
So (A + B) 1 day's work = (1/10+1/15)
= (3/30+2/30) = 5/30 = 1/6
So Both (A & B) together can finish work in 6 days