Question

If a and b can do a piece of work in 10 days and a alone can do it in 15 days, how long will b take to do it?

Answer 1

A B 10 days
A=15days 1/10-1/15. LCM of 10 and 15=30
3-2/30=1/30. 1÷1/30=30days


B=30days