Bartender

A brunette walks into a bar and says, "Gimme an M L."
The bartender says, "What's an M L?"

The brunette says, "A Miller Light."

Another brunette walks in and says, "Gimme a B L"

The bartender says, "What's a B L?"

She says, "Bud Light."

A dumb blonde walks in and says, "Gimme a 15."

The bartender says, "What's a fifteen?"

The blonde says, "7&7, duh!"