Working alone, printers X, Y, and Z can do a certain printing job, consisting of a large number of pages, in 16, 12, and 8 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?	Choose the correct choice from the following answers: A) 5/2 B) 7/4 C) 8/5 D) 10/3 E) 12/5
The time it takes printer X is 16 hours.   The combined rate of Y and Z is 1/12 + 1/8 = 5/24   The time it takes Y and Z is 24/5   The ratio of times is 16 / (24/5) = 5*16/24 = 10/3   The answer is 10/3.
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Working alone, printers X, Y, and Z can do a certain printing job, consisting of a large number of pages, in 16, 12, and 8 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?