Hi shibsriz,
This DS question can be solved by TESTing Values...
We're told that the average of 4 numbers is 30.
Sum/4 = 30
So the sum of the 4 numbers = 120. We're asked how many of the four numbers are greater than 30.
Fact 1: None of the numbers is greater than 60.
If the 4 numbers are...
30, 30, 30, 30 then the answer to the question is 0
29, 29, 31, 31 then the answer to the question is 2
Fact 1 is INSUFFICIENT
Fact 2: 2 of the numbers are 9 and 10.
Since those 2 numbers sum to 19, the other 2 numbers sum to 101.
If the remaining 2 numbers are...
0, 101 then the answer to the question is 1
31, 70 then the answer to the question is 2
Fact 2 is INSUFFICIENT
Combined, we know...
1) The two remaining numbers sum to 101
2) Neither of those two numbers is greater than 60
With those limitations, we could have....
41, 60 then the answer to the question is 2
42, 59 then the answer to the question is 2
43, 58 then the answer to the question is 2
Since neither of the numbers can be greater than 60, BOTH numbers MUST be greater than 30, so the answer to the question is ALWAYS 2.
Combined, SUFFICIENT
Final Answer: C
GMAT assassins aren't born, they're made,
Rich
