Bunuel wrote:
The Official Guide For GMAT® Quantitative Review, 2ND EditionAttachment:
Untitled.png
If l and w represent the length and width, respectively, of the rectangle above, what is the perimeter?
(1) 2l + w = 40
(2) l + w = 25
Target question: What is the perimeter?This is a great candidate for
REPHRASING the target question.
Aside: We have a free video with tips on rephrasing the target question (see below)
If L and W represent the rectangle's length and width, then the
perimeter = 2L + 2W.
So, we can REPHRASE the target question as...
REPHRASED target question: What is the value of 2L + 2W? Statement 1: 2L + W = 40 This statement does not
FEEL sufficient to answer the rephrased target question. So, I'm going to PLUG IN numbers.
There are several values of L and W that satisfy statement 1. Here are two:
Case a: L = 5 and W = 30, in which case
2L + 2W = 70Case b: L = 10 and W = 20, in which case
2L + 2W = 60Since we cannot answer the
REPHRASED target question with certainty, statement 1 is NOT SUFFICIENT
Statement 2: L + W = 25If we take this equation and multiply both sides by 2, we get:
2L + 2W = 50PERFECT - we have answered the REPHRASED target question!
Since we can answer the
REPHRASED target question with certainty, statement 2 is SUFFICIENT
Answer: B
Cheers,
Brent
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