one case can hold 3 boxes. each box can hold 3 binders. how many cases are needed to hold 126 binders?

The answer is 14 cases needed to hold 126 binders

3 boxes*3 binder capacity=9
You divide 126 by 9(126÷9)= 14 cases needed

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.