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sivaelectric
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With this type of yes no question, you generally want to try plugging in and elimination - show that the statements allow examples of both a yes and a no answer to the question stem, and are thus insufficient.sivaelectric wrote:Is X>0 and Y>0, is (X-a)/(Y-a) < X/Y?
1. X>Y
2. a>0
Let's go with an initial plug in of x=3, y=2 (x>Y to satisfy stat. (1). X/Y = 3/2, and from here it depends on the value of a.
IF a=1, then (3-1)/(2-1) = 2/1 = 2, and the answer is "no": 2 is not smaller than 3/2.
BUT
IF a=3, then (3-3) / 2-3) = 0/-1 = 0, and the answer is "yes": 0 is smaller than 3/2.
(BTW, the question has a bug, as it allows y-a to equal zero, thereby dividing by 0).
These values of a=1, a=3 satisfy both statements, so even the combination of statements still allows by a yes and a no answer, meaning that the combination is also insufficient and the answer is E.
