What is the value of x?

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Source: — Data Sufficiency |

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by Brent@GMATPrepNow » Mon Oct 22, 2012 8:51 pm
mbahound wrote:What is the value of x ?
1. y-x = y-6
2. x + 2y = 10
Target question: What is the value of x?

Statement 1: y-x = y-6
Subtract y from both sides to get: -x = -6
So, x = 6
Since we're able to answer the target question with certainty, statement 1 is SUFFICIENT

Statement 2: x + 2y = 10
Subtract 2y from both sides to get: x = 10 - 2y
As we can see, the value of x depends on the value of y. Since we don't know the value of y, we cannot determine the value of x
Since we're unable to answer the target question with certainty, statement 2 is NOT SUFFICIENT

Answer = A

Cheers,
Brent
Brent Hanneson - Creator of GMATPrepNow.com
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