Sale price is $75 it was 20% off what was the original price

Since it was 20% off, 75% is 80% (100-20) of something. We then want to find 10%, and multiply that by 10 to find the original price. Since 10% is 1/8th of 80, we divide 75 by 8 to get 9.375. Multiply that by 10 to get 93.75 dollars, the original price

Ok so the end equation here is going to be VCy-VCo=
air space. So we need to find the volume of the cone and the volume of the cylinder.

Lets start with the volume of the cylinder since its easiest. The volume of a cylinder is Pi*r^2*h = Volume.
We already know that the radius is 5 and the height is 16 so lets plug them in and solve. 3.14*5^2*16=1,256

Now lets solve to find the volume of the cone. Now this ones a bit harder, the equation is: Pi*r^2*(h/3)= Volume.
The radius is 4 and the height is 12, so now just solve! 3.14*4^2*(12/3)=201

Now we just need to subtract the Volume of the cylinder from the volume of the cone. 1,256-201=1,055

If you have any questions just ask!