Question

A and B can do a work in 12 days, B and C in 15
days, C and A in 20 days. If A, B and C work
together, they will complete the work in
(a) 5 days
(b) 7 (5/6) days
(c) 10 days
(d) 15 (2/3) days​

Answer 1

Answer:

A, B, C can complete the work in day= 1/2[(A+B)+(B+C)+(C+A)]=1/2[1/12+1/15+1/20]=1/10

Therefore A, B, C together can complete the work in 10 days.