Hi jjjinapinch,
We're told that R and T are both three-digit positive integers. We're asked if R is greater than T. This is a YES/NO question. We can solve it by TESTing VALUES.
1) The TENS digit of R is greater than each of the three digits of T.
IF....
R = 191 and T = 111, then the answer to the question is YES.
R = 191 and T = 888, then the answer to the question is NO.
Fact 1 is INSUFFICIENT
2) The TENS digit of R is less than either of the other two digits of R.
Fact 2 tells us NOTHING about the value of T, so there's no way to determine whether R is greater than T or not.
Fact 2 is INSUFFICIENT
Combined, we know:
-The TENS digit of R is greater than each of the three digits of T.
-The TENS digit of R is less than either of the other two digits of R.
With Fact 1, we know that the TENS digit of R is greater than all 3 digits in T, but we had no way to compare the HUNDREDS digits of R and T (so we didn't know which number was bigger). With the information in Fact 2 though, we know that the TENS digit of R is LESS than the HUNDREDS digit of R. Thus, we can create the following inequality:
(Hundreds digit of R) > (Tens digit of R) > (ANY digit in T)
eg. R = 870 and T = 512
Since the HUNDREDS digit of R is greater than EACH digit in T (including the HUNDREDS digit of T), R will ALWAYS be greater than T.
Combined, SUFFICIENT
Final Answer: C
GMAT assassins aren't born, they're made,
Rich
