There are 582 students at Cambridge Middle School. About 34% of the students chose blue as their favorite color.
About how many students chose blue?
A. 30
B. 150
C. 200
D. 250

The first one, i believe, would be correct. all the others have one thing in common, and that's that they have repeating numbers. in the second one, x and y have repeating 6's and 3's, and in the third, x and y have repeating 6's as well. in the last one, there are repeating 3's. the first one has no repeating numbers.

How many groups are there?