Data Sufficiency

Can someone help explain why the answer is E and not C? Is it because the two equations we set up from the 2 statements are not 2 distinct linear equations?


Machines X and Y work at their respective constant rates. How many more hours does it take machine Y, working alone, to fill a production order of a certain size than it takes machine X, working alone?

(1) Machines X and Y, working together, fill a production order of this size in two-thirds the time that machine X, working alone, does.

(2) Machine Y, working alone, fills a production order of this size in twice the time that machine X, working alone, does.

The two linear equations you about of are the same (Y=2X). Trying putting each of them in equation form and simplify it. You'll get the same equation both times. Therefore, we have one equation and 2 variables hence the answer.
Hope this helps.

According to me answer shud be E.
What is OA