Question

A bunch bowl is in the shape of a hemisphere. The top rim has a circumference of 116cm.

Answer 1

The hemisphere is half the volume of a sphere. Since we are given the circumference, we can solve for the radius of the sphere. That is 
     $C=2\pi r$

     $116\:cm=2\pi r$

     $r=\frac{116}{2\pi }=18.462\:cm$

Part A
We can now compute for the volume of the hemisphere.
     $V=\frac{1}{2}\times \frac{4}{3}\pi r^3=\frac{1}{2}\times \frac{4}{3}\pi \left(18.462\right)^3=13179\:cm^3$

Part B
We just need to convert the volume into its corresponding gallons
     $13179\:cm^3\times \frac{1\:Liter}{1000\:cm^3}\times \frac{1\:gallon}{3.785\:Liters}=3.5\:gallons$