Working alone, printers X, Y and Z can do a certain job, consisting of a large number of pages, in 12, 15 and 18 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 printer Y and Z to the the job, working together at their individual rates?
(A) 4/11
(B) 1/2
(C) 15/22
(D) 22/15
(E) 11/4
(A) 4/11
(B) 1/2
(C) 15/22
(D) 22/15
(E) 11/4
