Official Guide Explanation:
Data Sufficiency #24




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Solution and Metadata

Question: 24
Page: 274
Difficulty: 4 (Moderately Easy)
Category 1: Arithmetic > Properties of Integers > Evens and Odds

Explanation: Simplify each statement to isolate n.

Statement (1) is sufficient:

n2-1 = odd

n2 = odd + 1

n2 = even

Since n is an integer and n2 is even, n must be even as well.

Statement (2) is also sufficient:

3n + 4 = even

3n = even - 4

3n = even

If the product of two integers is even, at least one of the integers must be even. Since 3 is not even, n must be. Choice (D) is correct.

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