Does ab = a^2
(1) a^2 = b ^2
(2) a^3 = b ^3
[spoiler]OA=B[/spoiler].
Why is not sufficient the statement (1)? Can anyone give me a good explanation? I'd be thankful.
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Does ab = a^2
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Gmat_mission
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ab = a²Gmat_mission wrote:Does ab = a^2
(1) a^2 = b ^2
(2) a^3 = b ^3
0 = a² - ab
0 = a(a-b).
The resulting equation is valid only if a=0 or a=b.
Question stem, rephrased:
Does a=0 or a=b?
Statement 1:
If a=1 and b=1, then the answer to the rephrased question stem is YES.
If a=1 and b=-1, then the answer to the rephrased question stem is NO.
Since the answer is YES in the first case but NO in the second case, INSUFFICIENT.
Statement 2:
a³ = b³ implies that a=b.
Thus, the answer to the rephrased question stem is YES.
SUFFICIENT.
The correct answer is B.
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My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.
As a tutor, I don't simply teach you how I would approach problems.
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