Like most of these, the author is unknown.

A Longhorn, a Techster and an Aggie went into a bar for a drink. The longhorn tells the bartender, I’ll have a TC. The bartender says ”what’s that?” . The Longhorn says ”you know, a Tom Collins.” The Techster says ”I’ll have a PC.” The bartender says ”what’s that?” The Techster says “a Pina Colida.”

The Aggie says “I’ll have a 15.” The bartender says ”what’s that?” The aggie says “you know — seven & seven”.