Aman verma wrote:Brent@GMATPrepNow wrote:
This question is poorly worded.
Hi Brent,
Let's not get into semantics but rather focus on the logic of the problem. Okay, I have put appropriate punctuation marks in the options. The error occured due to oversight. I was a bit exhausted after day's work and missed those marks. It's midnight in India & I am bit drowsy. Nevertheless your post was helpful.
I'm not trying to be difficult, but poorly-worded GMAT-style questions have the potential to confuse students who are trying to study for an already-difficult test.
Even with the edits, the question has issues. The biggest issue is that various values of x can make more than 1 answer correct. For example, if x = 0, then x� + 16 = 16, and the expressions in answer choices A, B, C and D all evaluate to be factors of x� + 16.
Conversely, if x = 0.1, then x� + 16 = 16.0001
What are the factors of 16.0001?
Another issue is to suggest that the correct answer is
E - "Do not exist."
Does this mean that there are no factors of x� + 16?
If x is an integer, then we can be certain that 1 and (x� + 16?) are both factors.
To avoid ambiguity (and allow for only one correct answer), the question could read something like
Which if the following is equal to x^4 + 16 for all values of x?
(A) (x^2 + 4)(x^2 - 4)
(B) (x^2 + 4)(x^2 + 4)
(C) x(x^2 + 2)(x^4 + 4)
(D) (x^2 - 2)(x^2 + 2)
(E) none of the above
Answer:
E
Cheers,
Brent
