"What's the usual tip?" a man growled when a college boy delivered his pizza.
"Well," the student replied, "this is my first delivery, but the other guys said that if I got a quarter out of you, I'd be doing great."
"That so?" grunted the man. "In that case, here's five dollars."
"Thanks," the student said, "I'll put it in my college fund."
"By the way, what are you studying?"