Bottom's up

Idea for a drinking game:

Take number X, such as the number of participants. Multiply it by arbitrary number Y. If you get it wrong, you take a drink -- if you get it right, everyone else takes a drink. Then, the next person multiplies the previous result by a new number, chosen by the last person with a correct answer.

The game ends in forfeit or when everyone is so drunk that nobody can get a correct answer.