banksy wrote:

173. Is ab > 0?

(1) a – b > 0.

(2) a + b <0.

Try picking numbers and applying them considering different possible scenarios.

(1) a-b > 0

Case 1. a= -2 b= -5

a-b=-2-(-5)= 3. Condition satified.

So is ab>0? Yes.

Case 2. A= 5, B=(-3)

a-b= 5-(-3)= 8. Condition satisfied.

So is ab>0? No.

2 different answers. Hence this statement is insufficient.

(2) a+b<0

Case 1. a=- -10 , b= -5.

a+b=(-10-5)=-15. Condition Satisfied.

So is ab>0? Yes.

Case 2. a= -10 , b= 5

a+b= (-10+5)=-5. Condition satisfied.

So is ab>0?. No.

Again, 2 different answers. Hence this statement is also not sufficient.

1&2 Combined: Not sufficient as we can pick any combination of positive/ negative numbers.

Hence, the answer is E.

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