In the uncut version of the Friends episode The One At the Beach (Season 3, Episode 25) there's the following scene:
Phoebe: So, you’re all bored?
Phoebe: All right, I’m gonna close my eyes and point to someone, and you, whoever I point has to come up with something fun for us to do, and we have to do it.
(They do so, and Phoebe gets in the middle, closes her eyes, and starts spinning in a circle. She stops at Chandler)
Chandler: Okay, umm, we all have to play strip poker.
Monica: Chandler! Why, all of a sudden, do you wanna play strip poker?
Chandler: I think because of margaritas three, four, and nine.
What does Chandler mean by what he said? Why 3, 4 and 9?