Blonde, Brunette & Redhead Drinks Orders

A blonde, a brunette and a redhead went into a bar and asked the bartender:

Brunette: "I'll have a B and C."
Bartender: "What is a B and C?".
Brunette: "Bourbon and Coke."

Redhead: "And, I'll have a G and T."
Bartender: "What's a G and T?"
Redhead: "Gin and tonic."

Blonde: "I'll have a 15."
Bartender: "What's a 15?"
Blonde: "7 and 7"