Buying Drinks at a Bar

A blonde, a brunette and a redhead went into a bar and ordered their drinks from 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″