Posted by Cendrillion on .
A tennis ball can in the shape of a right circular cylinder holds 3 tennis balls snugly. If the radius is 3.5cm, what % of the tennis ball can is occuppied by air?
Where do I start?

geometry 
bobpursley,
I will be happy to critique your thinking on this.

geometry 
Cendrillion,
I used a visual and calcutated the height as 10.5cm. The radius would be half of the 3.5 to equal 1.75. I used the formul v=pie squared (x) height. I get 101.02 for the volume. I'm not sure what I am supposed to do next. Am I even approaching this the correct way?