Geometry Word Problem!

[isu23pink]

word problem:
"What is the volume of the empty space left when three tennis balls with a diameter of 3 in. are packed into a cylindrical container that is 9 in. tall with the same diameter as the tennis balls? Round your answer to the nearest tenth."

okay i totally think i screwed it up when i did it.
i got 60.75inches squared.

 

[mmm4444bot]

The units on the answer cannot be square inches; we're asked for a volume.

I was thinking that perhaps you used 3 as the radius, instead of 1.5, but doing that results in about 212 cubic inches.

However, if we drop the factor of Pi, then the 212 becomes 67.5 (which is somewhat close to your result).

Of course, it's a waste of my time trying to figure out what you did, when you don't show your work.

Here are the steps:

(1) Calculate the volume of ONE tennis ball

(2) Multiply the volume of one tennis ball by 3

(3) Calculate the volume of the cylinder

(4) Subtract the volume of three tennis balls from the volume of the cylinder.

I get 21.2 cubic inches.