55. Hannah is building a fence along 3 sides of a rectangle, leaving 1 of the short sides unfenced. The fence has a post at each corner. The rectangle is 30 feet by 48 feet, measured from the centers of the corner posts. As shown in the figure below, adjacent posts of the fence are set every 6 feet, and there are 12 wooden slats between each pair of posts. How many wooden slats will Hannah use for the fence?

Answer and Explanation

Your Answer is

Correct Answer is D

Explanation

6 feet can be used as a unit, and each 6 feet contains 12 slate.

For a long side, there are a total of 48÷6=8 units, that is to say, there are 8×12=96 slats in between, so there are 96×2=192 units in the two long sides slat; and for a short side, there are a total of 30÷6=5 units, that is to say, a short side has a total of 5×12=60 slats. So a total of 192+60=252 slats.