Question

How many ping-pong balls would it take to fill a classroom that measures 6 yards by 4 2/3 yards by 3 feet? (Assume a ping-pong ball has a radius of 0.75 inches and that the balls are stacked adjacent to and directly on top of each other.)

Answer 1

Answer: About 2,688 ping-pong balls

Explanation:

First, we will find how much space a ping-pong ball will take up.

-> A radius of 0.75 inches becomes a diameter of 1.5 inches

-> Then, we will pretend it is a cube with a side of 1.5 inches. Why? We do this because "the balls are stacked adjacent to and directly on top of each other."

V = a³

V = (1.5)³

V = 2.25 inches³

A ping-pong ball will take up 3.375 inches³.

Now, we will find the volume of the room.

V = L * W * H

V = 6 yards * 4
`(2)/(3)` yards * 3 feet

V = 18 feet * 14 feet * 3 feet

V = 756 feet³

Lastly, we will divide the room by a ping-pong ball to find the number of ping-pong balls:

756 feet³ / 3.375 inches³

9,072 inches³ / 3.375 inches³

2,688 ping-pong balls