A 10-by-12-inch page has margins of 1.5 inches on all sides. What fraction of the area of the page is taken up by the margins? Express your answer as a common fraction. Thanks!
Since you have a 1.5 in margin on both the left and the right, the center portion will be 10 - 1.5·2 = 7 inches wide.
With those margins on the top and the bottom, the center portion will be 12 - 1.5·2 = 9 inches tall.
The center portion has an area of 7 x 9 = 63 square inches.
The whole page has an area of 10 x 12 = 120 square inches.
Subtracting, we find that the margins have an area of 120 - 63 = 57 square inches.
The fraction of the page taken up by the margins is 57 / 120 = 19/40.