if 9 eggs makes 3 omelets, 6 eggs make 2 omelets, and 3 eggs make 1 omelet, how many omelets does 18 eggs make

Acone is placed inside a cylinder. the cone has half the radius of the cylinder, but the height of each figure is the same. the cone is tilted at an angle so its peak touches the edge of the cylinder’s base. what is the volume of the space remaining in the cylinder after the cone is placed inside it?