Hi sanjay12590,
I'm a big fan of TESTing THE ANSWERS (as Brent showcased). Like most Quant questions on the GMAT, you can answer this question in other ways though. Here's an approach that emphasizes the algebra involved:
We're told that the average of 4 numbers is 32..
Sum/4 = 32
Sum = 128
The prompt does NOT say that the numbers are distinct/unique/different, so we could possibly have duplicate numbers. We're also told that the range of the numbers is 12, so we know that the biggest number and smallest number are relatively close to one another. We're asked for what could be the largest number in the group. This is a "limit" question - to make one value as big as possible, we have to make the others as small as possible.
I'm going to call the first 3 numbers X; with a range of 12, the largest number would be X+12
X, X, X, X+12
We know the sum is 128 so....
X + X + X + X+12 = 128
4X + 12 = 128
4X = 116
X = 29
So one POSSIBLE set of numbers would be 29, 29, 29, and 41. 41 is not in the answers though, so we have to "play" with this group of numbers just a little bit.
If we took two of the 29s and turned them into 30s, then we could turn the other 29 into a 28 and the 41 into 40:
28, 30, 30, 40
Final Answer: A
GMAT assassins aren't born, they're made,
Rich
