Lee spends $9 on 3 comic books. each comic book costs the same amount

If he only spent 9$ total.. then 3x3=9 3$ each

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.