There are two ways you can use to answer this question, I'll put both so you can decide which makes sense to you:
1. You could say that for every foot, you go 0.25 inches (because 0.25 is 1/4) and therefore if you do 0.25 × 60, you get the length as 15 inches, and 0.25 × 7, you get the width as 7 inches.
2. You could think of it a different way, and say that if 0.25 inches is 1 foot, then 1 inch must be 4 feet. Using this logic, you can then divide 60 by 4 to get 15, and divide 28 by 4 to get 7.
Either way you use, you get the length as 15 inches, and the width as 7 inches. Hope this helps!