Our product and our sum always give the same answer. Who are we?

I am quite hot but become too cold if you remove the first two letters. What am I?

How is a fly different from a mosquito?

What is at the end of a rainbow?

What country can make you shiver?

The person who makes it has no need for it. He who purchases it does not use it. The person who does use it does not know they are. What is it?

My first is in chocolate but not in ham. My second is in cake and also in jam. My third at tea time is easily found. Altogether, this is a friend who is often around. What is it?

Can you find out which options fits best with the missing column?

A train leaves from point A for point B at 80 mph. After half an hour, another train leaves from point B for point A at 60 mph.

Which of the trains will be farther from point A when they meet ?

I have a hole in my back and legs I lack.
I live where I can’t breathe and I eat without teeth.
What am I?