A store sells small notebooks for $7 and large notebooks for $14. If a student buys 6 notebooks and spends $63, how many of each size did he buy?

L = 10 in

W = 2.5 in

Step-by-step explanation:

Let length be L and width be W

Perimeter = L + L + W + W

Perimeter =2L + 2W

given than length is 4 times the width, or

L = 4W (substitute this back into the perimeter equation above)

Perimeter =2L + 2W

Perimeter =2(4W) + 2W

Perimeter =8W + 2W

Perimeter = 10W

given that the perimeter is 25in

25 = 10W

W = 25 / 10 = 2.5 in  (answer for width)

L = 4W = 4(2.5) = 10 in (answer for length)