Answer:
B) 12
Step-by-step explanation:
Find h if r = 5 and V = 100π
First you ser up the equation for volume of a cone: 
Then you plug in your variables. In our case that is 5 for radius and 100π for volume.
So set up the equasion like this: 
Now multiply 5 by a power of 2 in order to get 25.
Your equsion should look like this: 
Multiply both sides by 3.

Then divide 300π by 25π.
This will leave you with h=12.