If you would like to know how much will Alice pay for carpet that costs $4.50 per square foot, you can calculate this using the following steps:
First, we have to find the area of the room by dividing the floor plan into two rectangles.
Calculating the area of the rectangle: multiplying the length with the width.
a ... area
l ... length
w ... width
First rectangle:
a1 = l * w = 7.5 ft * 5 ft = 37.5 square ft
Second rectangle:
a2 = l * w = 7.5 ft * 10 ft = 75 square ft
a = a1 + a2 = 37.5 + 75 = 112.5 square ft
Cost of the carpet: $4.50 per square foot
$4.50 per square foot * 112.5 square ft = 4.50 * 112.5 = $506.25
The correct result would be $506.25.