Working alone, Printers X, Y, and Z can do a certain printing job, consisting of a large number of pages, in 12, 40, and 50 hours, respectively. What is the ratio of the time it takes Printer X to do the job, working alone at its rate, to the time it takes Printers Y and Z to do the job, working together at their individual rates?
Options:
(A) 4/11
(B) 1/2
(C) 15/22
(D) 200/9
(E) 11/4 Think first, then make a decision. Some random thoughts:
P1 takes 12 hrs
Rate for P2P3 together = 1/40 + 1/50 = 9/200
Therefore they take 200/9
Ratio = 200/9 = So the answer is (D).