If 90/k is an integer, is k an integer?
(1) k > 1
(2) k is a multiple of a prime number.
[spoiler]OA=B[/spoiler]
Source: Princeton Review
If 90/k is an integer, is k an integer?
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Given: 90/k is an integerGmat_mission wrote:If 90/k is an integer, is k an integer?
(1) k > 1
(2) k is a multiple of a prime number.
Target question: Is k an integer?
Statement 1: k > 1
Let's TEST some values.
There are several values of k that satisfy statement 1. Here are two:
Case a: k = 10. Notice that 90/k = 90/10 = 9, which is an integer. In this case, the answer to the target question is YES, k IS an integer
Case b: k = 90/77. Notice that 90/k = 90/(90/77) = 90(77/90) = 77, which is an integer. In this case, the answer to the target question is NO, k is NOT an integer
ince we cannot answer the target question with certainty, statement 1 is NOT SUFFICIENT
Statement 2: k is a multiple of a prime number.
All prime numbers are INTEGERS, and all multiples of integers are integers.
So, the answer to the target question is YES, k IS an integer
Since we can answer the target question with certainty, statement 2 is SUFFICIENT
Answer: B
Cheers,
Brent