Hi kobel51,

This DS question is based on Algebra, specifically Classic Quadratics.

We're asked for the value of (a+b)^2, which is the same as asking for the value of a^2 + 2ab + b^2...

Fact 1: ab = 0

This ultimately means that either a or b or both = 0, but this is not enough info to answer the given question.
Fact 1 is INSUFFICIENT

Fact 2: (a-b)^2 = 36

This can be rewritten as a^2 - 2ab + b^2 = 36
It can also be thought of (a-b) = 6 OR -6
Unfortunately, none of this info is enough to answer the given question.
Fact 2 is INSUFFICIENT

Combined, we know that ab=0, so we can plug THAT into the formula from Fact 2 and into the given question:

Fact 2:
a^2 -(0) +b^2 = 36
Given Question:
a^2 - 0 + b^2 = 36

We can answer the given question.

Final Answer: C

GMAT assassins aren't born, they're made,
Rich