Question

A and b together can do a piece of work in 10days. B alone can do it in 15 days. In how many days can a alone do it?

Answer 1

Answer:30days

Step-by-step explanation:

A and B can together do the work in 10 days

So A and B's one day work=1/10

B can do the work in 15 days

So B's one day work=1/15

A's one day work=1/10-1/15=1/30

So A can do the work in 30days

Answer 2

A and B can do 1/10 of work in a day.

B can alone do 1/15 of work in a day.

Now

A=1/10-1/15

LCM of 15 and 10 is 30.

Therefore

A=3-2/30

=1/30

hence A can do a piece of work alone in 30 days