The equation in stmt 1 is fulfilled only if y-2 = 0, giving us y = 2. This does not help regarding the relationship between x and y, so 1 is insufficient.
The second equation helps establish that y = x + 1 or that y = -(x + 1). Since we cannot tell which case it really is, then this stmt is insufficient as well.
Put the two together and you get two cases from stmt 2:
a. y = x + 1 = 2 makes x = 1, which does not fit with the initial constraint that x is not 1
b. y = -(x + 1) = 2, making x = -1, which does fit with x being different from 1.
So I'd go with C.... Maybe I'm missing smth over here, I get a completely different answer....
variables
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Source: Beat The GMAT — Data Sufficiency |
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bluementor
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But we know that x is not equal to 1, and if y = 2, y will never be equal to x + 1. Isn't this sufficient to answer the question stem?DanaJ wrote:The equation in stmt 1 is fulfilled only if y-2 = 0, giving us y = 2. This does not help regarding the relationship between x and y, so 1 is insufficient.
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sureshbala
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Statement I alone is sufficient....naaga wrote:. If x ≠ 1, is y equal to x + 1?
(1) y-2/x-1 = 0
(2) y^2 = (x + 1)^2
folks I got the answer D
but the OA is A
can anyone explain
Look at this....
Given that y-2/x-1 = 0.
So y-2 =0 , i.e y =2.
Now, since y=2, y will be equal x+1 provided x=1. But in the statement it is clearly mentioned that x is not equal to 1. So x+1 is not equal to 2, where as y=2. So we can conclude that y is not equal to x+1.
Hence I is sufficient.
Coming to statement II, since y^2 = (x+!)^2, we have y= (x+1) or -(x+1). So II is not sufficient.
Hence A
