Question

A and B can do a given work in 8 days,B and C can do the same work in 12 days , and A,B,C complete it in 6 days. In how many days can A and C will finish the same work?

Answer 1

A+B 1 day work = 1/8
B+C 1 day work = 1/12
A+B+C 1 day work = 1/6

We can get A work by (A+B+C)-(B+C)
And C by (A+B+C)-(A+B)

So A 1 day work =
1/6−1/12=1/12

Similarly C 1 day work =
1/6−1/8=1/24

So A and C 1 day work =

1/12+1/24=1/8

So A and C can together do this work in 8 days