The 50-50-90 rule: Anytime you have a 50-50 chance of getting something right, there's a 90% probability you'll get it wrong.
Question #2274 posted on 01/12/2004 midnight
Q:

Dear 100 Hour Board,
How cold would air have to get in order to freeze?
- Frosty

A: Dear Frosty,

The three main components of air are nitrogen (~79%), oxygen (~20%), and carbon dioxide (~.03%). All the rest makes up so little of our air that it's inconsequential. Nitrogen, oxygen, and carbon dioxide each have different freezing points. Oxygen has the lowest, -368.77°F, so it would have to be that cold for all of the air to freeze. Just for your info, nitrogen freezes at -345.75°F and carbon dioxide freezes at -69.8°F.
Brrr, that's pretty cold. I get chilled if it's below 65.

PB&J
A: Dear Frosty,

Very.

- Popsicle man