What is the value of x ?
(1) y  x = y  6
(2) x + 2y = 10
OA A
Source: GMAT Prep
What is the value of x ?
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Target question: What is the value of x ?BTGmoderatorDC wrote: ↑Sun Dec 05, 2021 7:20 pmWhat is the value of x ?
(1) y  x = y  6
(2) x + 2y = 10
OA A
Source: GMAT Prep
Statement 1: y  x = y  6
Note: In most cases, there are infinitely many solutions to a linear equation with two variables. However, in this case, one of the variables cancels, leaving us an equation with ONE variable
Subtract y from both sides of the equation to get: x = 6
Multiply both sides of the equation by 1 to get: x = 6
Since we can answer the target question with certainty, statement 1 is SUFFICIENT
Statement 2: x + 2y = 10
This case, none of the variables cancel, which means there are infinitely many solutions to the equation x + 2y = 10
Here are two possible solutions:
Case a: x = 0 and y = 5. In this case, the answer to the target question is x = 0
Case b: x = 10 and y = 0. In this case, the answer to the target question is x = 10
Since we can’t answer the target question with certainty, statement 2 is NOT SUFFICIENT
Answer: A
Cheers,
Brent