Farrah earned a total of 15 appetizer recipes over the course of 3 weeks of culinary school. After how many weeks of culinarily school will Farrah know a total of 20 appetizer recipes?

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.

Jim has run 5/6 of a mile so far. i hope that answers your question! good luck : )