Question

ab can do a piece of work in 12 days b c can do it in 15 days will see and a can finish in 20 days in how many days will a b c finish it working together in how many days will each one of them finish it working alone​

Answer 1

A and B can do work in 12 days, B and C in 15 days, and C and A in 20 days. A B and C together can finish the whole work in 10 days. A, B, and C together can finish twice the whole work in 20 days. ∴ the correct answer is 20 days.