Is a > 0? Please explain...

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Is a > 0? Please explain...

by moonlite » Wed Sep 24, 2008 3:55 pm
Is a greater than 0 ?
(1) ab < 0 and a &#8722; b < 0.
(2) ac > 0 and c < 0.

Statement (1) ALONE is sufficient, but statement (2) ALONE is not sufficient.
Statement (2) ALONE is sufficient, but statement (1) ALONE is not sufficient.
BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
EACH statement ALONE is sufficient.
Statements (1) and (2) TOGETHER are NOT sufficient.

OA EACH statement ALONE is sufficient.



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by kris610 » Wed Sep 24, 2008 4:06 pm
A) tells you that a and b are of opposite signs and that a < b => a < 0.

B) tells you that a and c have the same sign and that c < 0 => a < 0.

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by kuroneko1313 » Wed Sep 24, 2008 4:06 pm
Statement 1:
ab < 0, this means either a or b must be smaller than 0.
a-b < 0, which means that a < b.
Again, a must be smaller than b while one of them must be negative. So b cannot be negative; therefore, a is negative. (Sufficient)

Statement 2:
ac > 0, this means either both a and c are positive or negative.
c < 0, then a is also smaller than 0. (Sufficient)