Math Jokes

A physicist, a mathematician and an engineer, are staying in a hotel. At midnight, the engineer smells smoke. He goes out into the hallway and sees a fire. He fills a trash can from his room with water, douses the fire and goes to sleep again.
Later, the physicist wakes up and smells smoke. He opens his door and sees a fire in the hallway. He gets the fire hose and, after calculating the flame velocity, distance, water pressure, trajectory, etc., extinguishes the fire with the minimum amount of water and energy needed.
Finally, the mathematician wakes up and smells smoke. He goes to the hall, sees the fire and then the fire hose. He thinks for a moment and then exclaims, "Ah, a solution exists!" and then goes back to bed and continues his sleep.

Q: What do you get if you divide the circumference of a jack-o-lantern by its diameter?
A: Pumpkin Pi!

Q: Why do mathematicians, after a dinner at a Chinese restaurant, always take the leftovers home?
A: Because they know the Chinese remainder theorem!

A math student is bothered by a classmate who wants to copy his homework. The student hesitates. He thinks it's wrong and is also concerned about being sanctioned for aiding and abetting.
His classmate says: "Nobody will be able to trace my homework to you: I'll change the names of all the constants and variables: a to b, x to y, and so on."
Though not fully convinced, the student gives his assignment to the classmate.
Later, the student asks: "Did you really change the names of all the variables?"
"Sure!" the classmate replies. "When you called a function f, I called it g; when you took variable x, I renamed it to y. When you were writing about the log of x+1, I called it the timber of x+1..."