Bunuel wrote:
What is the value of positive integer x?
(1) x^w=1
(2) w is even
Kudos for a correct solution.
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 = 1Case b: x = 2 and w = 0. In this case, the answer to the target question is
x = 2Since 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 evenSince 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 = 1Case b: x = 2 and w = 0. In this case, the answer to the target question is
x = 2Since we cannot answer the
target question with certainty, the combined statements are NOT SUFFICIENT
Answer: E
Cheers,
Brent