alphonsa wrote:
Integers a and b are such that a-b> 0
Is |a| > |b| ?
1) ab> 0
2) a+b = 12
Source : 4Gmat
Start with the question. Do some algebra, move the b to the other side of the inequality and you can quickly figure out that a > b.
Next, we look at statement 1:
ab > 0
This means that a and b are positive or both are negative.
The question is asking about absolute values. Therefore we have to consider that in the negative values, the smaller the number, the greater its absolute value. Therefore, since we don't know whether a and be are positive or negative, we have to say statement 1 is insufficient.
Examples:
a= 2
b = 1
TRUE
a=-2
b=-3
FALSE
INSUFFICIENT
Eliminate A, D.
Next, we do statement 2:
The question tells us that b < a.
a+b = 12.
If b < a, then a can't be a negative number, otherwise statement 2 would not hold true. Therefore a is positive, and |b| must also be less than a.
SUFFICIENT
Correct answer is B.