If ab=ac is b=2?
(1) c=1
(2) a is a prime number and c is NOT a prime number
OA:B
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If ab=ac is b=2?
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ab = acNandishSS wrote:If ab=ac is b=2?
(1) c=1
(2) a is a prime number and c is NOT a prime number
ab - ac = 0
a(b-c) = 0.
The resulting equation is valid only if a=0 or b=c.
Implication:
If a=0, then b can be ANY VALUE.
If a≠0, then b=c.
Statement 1:
Case 1: a=0, b=2, c=1
In this case, the answer to the question stem is YES.
Case 2: a=0, b=1, c=1
In this case, the answer to the question stem is NO.
INSUFFICIENT.
Statement 2:
Since a≠0, b=c.
Since c is not a prime number -- and b and c are equal -- b cannot be a prime number.
Thus, b≠2, and the answer to the question stem is NO.
SUFFICIENT.
The correct answer is B.
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As a tutor, I don't simply teach you how I would approach problems.
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