Convert it into an improper fraction. Find your common denominator then subtract. If this doesn’t help let me know.
Jeff because it was out of 5 and he only had two so he had three more to go. Jane had 1 more to go. Jill had 1 more to go. Cindy had 1 more to go and Jeff has 3 more to go.
The sum of two adjacent sides is 11 inches, so the long sides are 9 inches. The "unknown number" must be 12.