A, B and C can do a piece of work in10 days, 12 days and 15 days respectively. How long will they take to finish it if they work together?

A can do a piece of work in 10 days and B in 15 days. How long will they take to finish it working together ?

A and B can finish a piece of work in 12 days, B and C in 15 days shile C and A in 20 days. How long will they take to finish it together ? How long will each take to finish the work alone ?

A can do a piece of work in 10 days and B can do the same work in 12 days. How long will they take to finish the work, if both work together?

A, B and C can finish a piece of work in 12 days, 15 days and 20 days respectively. They started working together. B left the work after working 3 days and C left the work 3 days before completion of the work. In how many days work will be finished?

If A, B, and C can do a piece of work in 15, 30, and 60 days respectively. In how many days together they will do the same work?

Raj can do a piece of work in 20 days and Rohan can do it in 12 days. How long will they take, if both work together?