Subject :IMO Class : Class 7
A and B can do a work in 12 days, B and C is 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) 
(C) 10 days
(D) 
Ans 1:
Class : Class 7
option c