Data Sufficiency

HI prata,

This DQ question can be solved by TESTing VALUES.

We're told that K is an INTEGER. We're asked if it's greater than 3. This is a YES/NO question.

1) The sum of -4 and K equals the SQUARE of an INTEGER.

To start, I'm going to list out the first few squares of integers: 0, 1, 4, 9, 16, etc.

IF...
the sum = 0, then K=4 and the answer to the question is YES
the sum = 1, then K=5 and the answer to the question is YES
the sum = 4, then K=8 and the answer to the question is YES
etc.

As the square gets bigger, K gets bigger (and the answer to the question will be YES every time).
Fact 1 is SUFFICIENT

(2) K equals the square of an integer.

IF...
K = 0, then the answer to the question is NO.
K = 4, then the answer to the question is YES.
Fact 2 is INSUFFICIENT

Final Answer: A

GMAT assassins aren't born, they're made,
Rich

prata wrote:Is the integer k greater than 3?

(1) The sum of -4 and k equals the square of an integer.

(2) k equals the square of an integer.

[spoiler]OA: A[/spoiler]

We need to determine whether the integer k is greater than 3.

Statement One Alone:

The sum of -4 and k equals the square of an integer.

The smallest square of an integer is 0 since 0 = 0^2. Any other square of an integer will be greater than 0. Therefore, the sum of -4 and k is at least 0, that is, -4 + k ≥ 0. Solving this inequality we have k ≥ 4.

Since k is greater than or equal to 4, k is greater than 3. Statement one alone is sufficient. Eliminate answer choices B, C and E.

Statement Two Alone:

k equals the square of an integer.

If k equals the square of an integer, k could be greater than 3 or it could be less than 3.

For example, if k = 2^2 = 4, then it is greater than 3. However, if k = 1^2 = 1, then it is less than 3. Statement two alone is not sufficient.

Answer:A