BTGModeratorVI wrote: ↑Wed Oct 07, 2020 7:11 am
What is the value of positive integer x?
(1) x^w=1
(2) w is even
Answer:
E
Source: Veritas Prep
Target question: What is the value of positive integer x?
Statement 1: x^w=1
This statement doesn't FEEL sufficient, so I'll TEST some values.
There are several values of x and w that satisfy statement 1. Here are two:
Case a: x = 1 and w = 2. In this case, the answer to the target question is
x = 1
Case b: x = 2 and w = 0. In this case, the answer to the target question is
x = 2
Since we cannot answer the
target question with certainty, statement 1 is NOT SUFFICIENT
Aside: For more on this idea of testing values when a statement doesn't feel sufficient, read my article: https://www.gmatprepnow.com/articles/dat ... lug-values
Statement 2: w is even
Since we have no information about x, it's impossible to answer the
target question with certainty
So, statement 2 is NOT SUFFICIENT
Statements 1 and 2 combined
At this point, I recognize that we can re-use the values we used to show that statement one is not sufficient, since w is even in both of those cases.
So, the same counter-examples will satisfy the two statements COMBINED.
In other words,
Case a: x = 1 and w = 2. In this case, the answer to the target question is
x = 1
Case b: x = 2 and w = 0. In this case, the answer to the target question is
x = 2
Since we cannot answer the
target question with certainty, the combined statements are NOT SUFFICIENT
Answer: E
Cheers,
Brent
Brent Hanneson - Creator of GMATPrepNow.com
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