OG 11th edition, practice question #125

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by bingojohn » Thu Aug 09, 2007 7:51 am
gabriel wrote:
UmanG wrote:
.. Let say r =12 = 2*2*3 and s = 6 = 2*3

Here still statement given in the question "every factor of s also a factor of r" holds and still both the number are not same...



OMG :shock: .. i cant believe that i just did that .. ur right .. i dont know what i was thinking when i wrote that post ... bcoz i myself dont agree with that post :wink: ..

.. anyway as u mentioned in ur post the answer A still holds ..
Good discussion guys... thanks for the help...

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by Kansonne » Fri Dec 28, 2007 4:19 pm
Hi---

Was anyone else confused like me on the wording of this problem?

I had no issues with (1) being sufficient. I had originally thought D was the answer. For me the confusion was in the differences between (1) and (2) as to what counts as "every" whatever factor.

Interpretation #1 (Correct according to the OA)-

If r = 6 and s = 12,

r= 2 * 3
____________
s= 2 * 2 * 3

s contains two DISTINCT prime factors, 2 and 3.
r contains two DISTINCT prime factors, 2 and 3.

r/s could be integer or a fraction. Insufficient.

Interpretation #2 (Not correct)-


r= 2 * 2 * 3 <----...which means that r must have those SAME factors in the SAME quantities.
____________
s= 2 * 2 * 3 <----s has two 2's and 1 three for prime factors...


Sufficient.
__________________________________________________
I guess my question is this, how are we to know when the GMAT is asking for the same factors (the number 12 has 2 and 3 for prime factors as does the number 6.) vs. the same factors in the same quantities (12 has two powers of 2 and one power of 3 but 6 only has one power of two and one power of 3)?

Thx.

K