Elaine has a desktop that is 4.5 feet by 5.5 feet, and she is going to cover it with patches of wallpaper that each measure 18 inches wide and 24 inches long. how many patches will Elaine need to cover the entire desktop? justify your answer.

first transform feet into inches 4.5 feet = 48.5 inches; 5.5 feet = 60.5 inches;

then get the area in inches : 48.5 x 60.5 = 2934.25 inches; the area of one patch is 18 x 24 = 432 inches

so now divide the area of the desktop by the area of one patch

2934.25 / 432 = 6.7 so she needs 7 patches