I am needing help with this problem. My teacher says its wrong but I keep getting the same answer every time.

Question

The length of a wall is 11 feet 3 inches. A shelf will be built on the center of the wall, and the length of the shelf will be a 1/3 the length of the wall. What is the distance in inches from the edge of the wall to the edge of the shelf?

Answer 1

This becomes clear if you draw and label a picture of the situation.

length of wall is 11 ft 3 inches = [11(12)+3] inches = 135 inches

length of shelf is 135/3 inches = 45 inches

The edge of the shelf is 45/2 inches from the center of the wall.

45/2 inches = 22.5 inches

Now subtract this from half the length of the wall to get the distance from the edge of the shelf to the edge of the wall.

(135/2 - 22.5) inches = (67.5 - 22.5) inches = 45 inches