A and B can together complete a piece of work in 4 days. If A can alone can complete the same work in 12 days, in how many days can B alone complete that work?
Options:
(A) 6
(B) 5
(C) 4
(D) 3
(E) 2 Think first, then make a decision. Some random thoughts:
(A+B)'s 1 day work = 1/4
A's 1 day work = 1/12
B's 1 day work = 1/6 So the answer is (A).