Question: GCD of x and y is 12

Comment on GCD of x and y is 12

Why couldn't the answer be 48?
greenlight-admin's picture

Keep in mind that we're looking for an answer choice that MUST be true.

If the greatest common divisor of x and y is 12, then it COULD be the case that x = 12 and y = 12
If x = 12 and y = 12, then 2x = 24 and 2y = 24, and the greatest common divisor of 24 and 24 is 24.
So it need not be the case that the GCD is 48

Hi Brent, is it least common divisor or GCD in your solution above? because the least common divisor of 24 and 24 will be 2.
greenlight-admin's picture

Good catch! I meant to say GREATEST common divisor. I've edited my comment above.
Thanks for the heads up!

Aside: The least common divisor of ANY two positive integers will always be 1.

Thanks Brent!!

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