If y is an integer, is y^3 divisible by 9?
(1) y is divisible by 4.
(2) y is divisible by 6.
The OA is B .
Experts, how can I show that statement (1) is not sufficient?
If y is an integer, is y^3 divisible by 9?
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(1) y is divisible by 4.VJesus12 wrote:If y is an integer, is y^3 divisible by 9?
(1) y is divisible by 4.
(2) y is divisible by 6.
The OA is B .
Experts, how can I show that statement (1) is not sufficient?
Say y = 4k; where k is an integer
Thus, y^3 = 64k^3
If k^3 is divisible by 9, the answer is Yes, else No. Insufficient.
(2) y is divisible by 6.
Say y = 6k; where k is an integer
Thus, y^3 = 6^3k^3 = (2*3)^3k^3 = 2^3*3^3k^3
Since 3^3 is divisible by 9, the answer is Yes, else No. Sufficient.
The correct answer: B
Hope this helps!
-Jay
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