Working alone, printers X,Y, Z can do a certain printing 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 printers Y and Z to do the job, working together at their individual rates?
A) 4/11
B) 1/2
C) 15/22
D) 22/15
E) 11/4
The answer is D.(I don't know how to use the spoiler to hide the answer. Please guide me)
I don't understand the part why x is 12/1 instead of 1/12? Can someone please explain it to me?
Thank you in advance.
A) 4/11
B) 1/2
C) 15/22
D) 22/15
E) 11/4
The answer is D.(I don't know how to use the spoiler to hide the answer. Please guide me)
I don't understand the part why x is 12/1 instead of 1/12? Can someone please explain it to me?
Thank you in advance.
