gmatt1476 wrote:
Is x an integer?
(1) x² is an integer.
(2) x/2 is not an integer.
DS73402.01
Target question: Is x an integer? Statement 1: x² is an integer. Let's TEST some values.
There are several values of x that satisfy statement 1. Here are two:
Case a: x = 1. In this case, the answer to the target question is
YES, x IS an integerCase b: x = √2. In this case, the answer to the target question is
NO, x is NOT an integerSince we cannot answer the
target question with certainty, statement 1 is NOT SUFFICIENT
Statement 2: x/2 is not an integer.NOTE: Notice that we can re-use the same counterexamples from statement 1.
Case a: x = 1. In this case, the answer to the target question is
YES, x IS an integerCase b: x = √2. In this case, the answer to the target question is
NO, x is NOT an integerSince we cannot answer the
target question with certainty, statement 2 is NOT SUFFICIENT
Statements 1 and 2 combined IMPORTANT: Since I was able to use the
same counter-examples to show that each statement ALONE is not sufficient, the same counter-examples will satisfy the two statements COMBINED.
So, the combined statements are NOT SUFFICIENT
Answer: E
Cheers,
Brent
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