A and B can do a work in 12 days. B and C can do it is 15 days and A and C can do it in 20 days. If all of them work together...
Answer:
10
A and B can do a work in 12 days. B and C can do it is 15 days and A and C can do it in 20 days. If all of them work together, in how many days they can finish the work?