Hi M7MBA,

We're told that Set A has 20 numbers and B has 40 numbers. We're asked if the range of B is greater than 45. This is a YES/NO question. We can TEST VALUES to answer this question.

1) The range of A and B combined exceeds 50

IF....
Set A = integers 1-20, inclusive and Set B = 21-60, inclusive, then the answer to the question is NO.
Set A = integers 1-20, inclusive and Set B = even integers 20-98, inclusive, then the answer to the question is YES. Fact 1 is INSUFFICIENT

2) Range of B is greater than range of A

Both of the TESTs that we used for Fact 1 also 'fit' Fact 2:
IF....
Set A = integers 1-20, inclusive and Set B = 21-60, inclusive, then the answer to the question is NO.
Set A = integers 1-20, inclusive and Set B = even integers 20-98, inclusive, then the answer to the question is YES.
Fact 2 is INSUFFICIENT

Combined, there's no more work to be done. We already have two different TESTs that 'fit' both Facts and produce different answers (one "NO" and one "YES").
Combined, INSUFFICIENT.

Final Answer: E

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