Bunuel wrote:

Is y an integer?

(1) When y is divided by two, the result is the square of an integer.

(2) When y is multiplied by two, the result is the square of an integer

As this question has almost no technical details (numbers/equations) we'll look for a Logical approach.

(1) We'll start from the end: the square of an integer must be an integer.

Since an integer times 2 is still an integer, y must also be an integer.

Sufficient!

(2) Similarly to the above, the square of an integer is an integer.

However, without knowing if this integer is divisible by 2, we can't know if y is an integer or not.

Insufficient!

(A) is our answer.

_________________

David

Senior tutor at examPAL

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