Hi M7MBA,
We're told that |X - Y| = 5. We're asked for the value of X. This question can be solved with a bit of Arithmetic and TESTing VALUES.
1) Y = 5
With the information in Fact 1, we have the equation |X - 5| = 5. This equation has TWO solutions: 10 and 0
|10 - 5| = 5
|0 - 5| = |-5| = 5
Fact 1 is INSUFFICIENT
2) X > 0
With Fact 2, we know that X is POSITIVE, but that does not limit the number of possible solutions (since Y can be anything).
Fact 2 is INSUFFICIENT
Combined, we know...
Y = 5 and X = 10 or 0
X > 0
The ONLY solution that 'fits' both Facts is X=10
Final Answer: C
GMAT assassins aren't born, they're made,
Rich