Guy on Street #2: It's 3:00. Where the hell is Louie?
Guy on Street #1: Well, you tell me. Louie left his house at 2:15 and had to travel a distance 6.2 miles traveling at a rate of five miles a hour. When will Louie get here?
Guy On Street #2: Depends if he stops to see his ho.
Guy on Street #1: That's what we call a "variable".