Pencils come in packages of 10. erasers come in packages of 12. phillip wants to purchase the smallest number of pencils and erasers so that he will have exactly 1 eraser per pencil. how many packages of pencils and erasers should phillip buy?

One of each. So buy 1 pack of both

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.