Hi M7MBA,
We're given the definition of a “digifac” number - each of its DIGITS is a factor of the number itself. We're asked for the sum of the missing two digits of the following five-digit digifac: 9, 5, 3 _ _ ? This question is based on several Number Property Rules.
For '5' to be a factor of this 5-digit number, the number must end in either a 0 or a 5.
For '9' to be a factor of this 5-digit number, the digits must SUM to a number that is divisible by 9.
Any number that is divisible by 9 will also be divisible by 3, so no extra work is required here.
IF.... the 5-digit number was....
9 5 3 _ 0 .... then the sum of the digits would be 17 and the missing digit would need to be a 1. However, with 95310.... '0' is NOT a factor of 95310, so this is NOT a possible solution.
9 5 3 _ 5 .... then the sum of the digits would be 22 and the missing digit would need to be a 5. With 95355, the sum of the digits is 27 and all of the digits IS a factor of the 5-digit number. Thus, the sum of the missing digits is 5+5 = 10
Final Answer: D
GMAT assassins aren't born, they're made,
Rich
