Is a/b >0?

[M7MBA]

Is a/b >0?

(1) ab > 0
(2) b/a > 0

The OA is D.

How can I prove that each statement alone is sufficient? Should I use particular numbers or it can be solved for a and b general?

[Jay@ManhattanReview]

Is a/b > 0?

(1) ab > 0
(2) b/a > 0

The OA is D.

How can I prove that each statement alone is sufficient? Should I use particular numbers or it can be solved for a and b general?

We have to determine whether a/b > 0.

Let's take each statement one by one.

(1) ab > 0

=> a and b both are either postive or negative.

Case 1: Say a and b both are postive, then we have a/b = |a|/|b| = positive quantity > 0. The answer is Yes.
Case 2: Say a and b both are negative, then we have a/b = (-|a|) / (-|b|) = |a|/|b| = positive quantity > 0. The answer is Yes.

Sufficient.

(2) b/a > 0

=> a and b both are either postive or negative.

Case 1: Say a and b both are postive, then we have a/b = |a|/|b| = positive quantity > 0. The answer is Yes.
Case 2: Say a and b both are negative, then we have a/b = (-|a|) / (-|b|) = |a|/|b| = positive quantity > 0. The answer is Yes.

Sufficient.

The correct answer: D

Hope this helps!

-Jay
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