Fun Riddles

Question: A man finds a small iron coin dated 154 B.C., what's it worth?

Question: I'm number three.
But I'm not a number.
I'm hot and cold at the same moment but not at the same time.
I'm number three.
But I'm not a number.

Who or what am I?

Question:

Take me for a spin and I'll make you cool,
but use me when it's cool and you're a fool.

What am I?

Question: It smells like blue paint,
pours like green paint,
and it looks like a red truck.

What is it?

Question: Enter one hole and leave three,
once you succeed I'm on thee?

What am I?