BTGmoderatorDC wrote:If a and b are positive integers, is the product ab odd?
(1) b = 3
(2) a and b are consecutive integers.
OA B
Source: Princeton Review
Given a and b are positive integers, for the product ab to be odd, a as well as b must be odd. Even if only one of the two is even, the product ab is odd.
Let's take each statement one by one.
(1) b = 3
Even a is even, ab is even; however, if a is odd, the product is odd. Insufficient.
(2) a and b are consecutive integers.
Given that a and b are consecutive integers, one between a and b would be even and the other would be odd; thus, the product ab = even. The answer is no. Sufficient.
The correct answer:
B
Hope this helps!
-Jay
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