Where do you go to learn how to make ice cream?

Forwards I am heavy, backward I am not. What am I?

When does a USA Potato change its nationality?

If you had a pizza with crust thickness 'a' and radius 'z', what's the volume of the pizza?

You’ll find me on Mercury, Earth, Mars, Jupiter, Saturn, and Uranus. But never Neptune, or Venus. What am I?

I cannot talk, but I always reply when spoken to. What am I?

It's a 7-letter word.
If we remove 1 letter from it, it remains the same.
If we remove 2 letters from it, it remains the same.
If we remove 3 letters from it, it remains the same.
If we remove all the letters from it, still it remains the same.
What is it?

There are three houses in a straight row. One is red, one is blue, and one is white. The red house is left of the middle. The blue house is right of the middle. Where's the white house?

What can you serve, but never eat?

What is the coolest letter in the alphabet?