To answer this question, you need to know the formula for calculating the volume of cone and cylinder. The formula should look like this:
cone volume: π * r^2 * h/3
cylinder volume: π * r^2 * h
Now if you compare both of them with information that the radius and height is same, then the cone:cylinder volume ratio would be:
Cone volume/cylinder volume=
π * r^2 * h/3 / π * r^2 * h= 1/3
Cone volume is 1/3 of cylinder volume