tom ate one-third of the candies in a box. Roger ate two-fifths of the remaining candies. There were 18 candies left. How many candies were in the box to start with?

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.