Question

if A can do a work in 10 days and B can do a work in 15 days then in how many day both can do the work together?

Answer 1

A complets the work in 10 days
The part of the work finished by A in 1 day = 1/10
B complets the work in 15days
The part of the work finished by B in 1 day =1/15
Part of the workA and B together finish the in 1day =1/10+1/15

=(15+10)/150
=25/150
=1/6
Therefore A and B together complete the work in 6 days