gmat prep num props

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gmat prep num props

by vinviper1 » Sun Jun 08, 2008 6:48 pm
Was unsure of III. Thanks.
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by sudhir_83k » Sun Jun 08, 2008 11:01 pm
Is the answer to this question is 1st option only.

please advice.

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by VerbalAttack » Sun Jun 08, 2008 11:28 pm
Hi vinviper1,

I & II are obvious and both are correct (satisfy the rule).

As for III, either you expand the equation i.e., apply a@b formula for (a@b)@c and a@(b@c) and make sure both are same or pick numbers to solve faster; i assumed a=1, b=1, c=1 and a=1, b=2, c=3 (second set is just to double check). You can assume any numbers.

both prove that III is also correct.

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by vinviper1 » Mon Jun 09, 2008 7:48 pm
Ah! Got strategy.

The answer is all of the above.

Thanks all.