Question

A cross section is cut from a brass cylinder with walls that are 2 centimeters thick. The radius of the cross section, measured to the outer portion of the ring, is 5.5 centimeters. What is the maximum volume of a ball that could pass through the interior of the brass ring?

Answer 1

Here, Radius to the inner portion = Radius to outer portion - thickness
r = 5.5 - 2 = 3.5 cm

Now, ball with radius of 3.5 cm can pass through the ring. 
So, volume = 4/3 πr³
v = 4/3 * 3.14 * (3.5)³
v = 4.186 * 42.875
v = 179.50 cm³

In short, Your Answer would be: 179.50 cm³

Hope this helps!