First, add the numbers under the square root sign: 66 + 85 = 151. Then take the square root
of that. Stop! Don’t have a panic attack right here. No, you aren’t allowed to use a calculator.
That’s the bad news. The good news is that you don’t have to. You don’t need to get an exact
answer for a QC problem; you just have to compare the quantities in the columns.
Look for a perfect square close to 151. How about 144, which is 122, or 169, which is 132?
Because 151 is between 144 and 169, the square root of it must be between 12 and 13. You
couldn’t care less exactly what it is. (That’s right — don’t bother finding the exact square
root!) As long as it’s more than 12, Column A is larger. Correct Answer: A.