Question

a and b can do a piece of work in 9 days , B and C can do it in 15 days and A and C can do it in 8 days to finish . how much time will A , B and C take to finish the work separately

Answer 1

Let xx be the amount of work.

Amount of work B can do in one day is x15x15. 

So in 10 days, B did 10x1510x15.

So in 10 days, A did x−10x15=5x15x−10x15=5x15

So amount of work A can do in one day is 5x10∗15=x305x10∗15=x30  ( above divided by 10 )

To do x30x30 work, it takes A 1 day.

So to do xx work, A will take x∗1x30=30x∗1x30=30 days.