Hi Bunnel
i didnt understand the explanation for st 2 in revised qs.
(2) a^2 is even --> a^2=even --> a=\sqrt{even}, so a is either even (for example if a^2=4) or an irrational number (for example if a^2=6). Sufficient. Generally a^2 to be an integer a must be either an integer or an irrational number (for example: \sqrt{3}), (notice that a can not be reduced fraction, for example \frac{2}{3} or \frac{11}{3} as in this case a^2 won't be an integer).
the qs is asking if a is even... if a^2 = 6... then also a is even right? as the qs doesnt mention integer anywhere.
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Hope to clear it this time!!
GMAT 1: 540
Preparing again