Hi,
Could you guys help me understand why the answer for this DS question isn't D, but C?
What is the numerical value of x^2 - 25?
(1) x - 5 = 3
(2) 4 - x = 5
Thanks,
Marcelo
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DS Numerical Value
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Brent@GMATPrepNow
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Are you sure you transcribed the question correctly?MarceloBR wrote:Hi,
Could you guys help me understand why the answer for this DS question isn't D, but C?
What is the numerical value of x^2 - 25?
(1) x - 5 = 3
(2) 4 - x = 5
Thanks,
Marcelo
The statements in DS questions shouldn't contradict each other (statement 1 tells us that x = 8, but statement 2 tells us that x = -1).
Cheers,
Brent
Brent Hanneson - Creator of GMATPrepNow.com
Hi, Brent!
It was correct!
I pasted below the answer given by the tutorial:
"Since x^2 - 25 is the difference between two perfect squares, its factors are (x - 5) and (x + 5). Statement(1) gives the value of x - 5. Statement (2) can be changed from 4 - x = 5 to 4 = x + 5 by adding x to both sides of the equation. Since you now know the numerical value of each factor, you can find the numerical value of x^2 - 25"
Thanks for such a quick reply!
It was correct!
I pasted below the answer given by the tutorial:
"Since x^2 - 25 is the difference between two perfect squares, its factors are (x - 5) and (x + 5). Statement(1) gives the value of x - 5. Statement (2) can be changed from 4 - x = 5 to 4 = x + 5 by adding x to both sides of the equation. Since you now know the numerical value of each factor, you can find the numerical value of x^2 - 25"
Thanks for such a quick reply!
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Hi MarceloBR,
There's something wrong with the way this question has been written (or transcribed).
In DS questions, if BOTH Facts are SUFFICIENT, then they should both have the SAME answer.
In this prompt, Fact 1 and Fact 2 have DIFFERENT answers, so they can't both be sufficient. Thus, something is wrong either with the original question or how it was transcribed.
GMAT assassins aren't born, they're made,
Rich
There's something wrong with the way this question has been written (or transcribed).
In DS questions, if BOTH Facts are SUFFICIENT, then they should both have the SAME answer.
In this prompt, Fact 1 and Fact 2 have DIFFERENT answers, so they can't both be sufficient. Thus, something is wrong either with the original question or how it was transcribed.
GMAT assassins aren't born, they're made,
Rich
