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Source: — Data Sufficiency |

by Brent@GMATPrepNow » Wed Aug 01, 2018 4:17 pm
vaibhav101 wrote:if x = y/7, then is x < 30?
1) y > 210
2) y < 217
Given: x = y/7

Target question: Is x < 30?
This is a good candidate for rephrasing the target question.
Since x = y/7, we can replace x with y/7 to get...
REPHRASED target question: Is y/7 < 30?
Let's rephrase the target question even more....
Take: y/7 < 30
Multiply both sides by 7 to get: y < 210

RE-REPHRASED target question: Is y < 210?

Statement 1: y > 210
If y > 210, then the answer to the RE-REPHRASED target question is NO, y is NOT less than 210
Since we can answer the target question with certainty, statement 1 is SUFFICIENT

Statement 2: y < 217
There are several values of y that satisfy statement 2. Here are two:
Case a: y = 216, in which case, the answer to the RE-REPHRASED target question is NO, y is NOT less than 210
Case b: y = 200, in which case, the answer to the RE-REPHRASED target question is YES, y IS less than 210
Since we cannot answer the RE-REPHRASED target question with certainty, statement 2 is NOT SUFFICIENT

Aside: Here's a video with tips on rephrasing the target question: https://www.gmatprepnow.com/module/gmat- ... cy?id=1100

Answer: A

Cheers,
Brent
Brent Hanneson - Creator of GMATPrepNow.com
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