[Yes, I know, these jokes are nearly the same. I also like multiple proofs of the same theorem.] Three employees (an engineer, a physicist and a mathematician) are staying in a hotel while attending a technical seminar. The engineer wakes up and smells smoke. He goes out into the hallway and sees a fire, so he fills a trashcan from his room with water and douses the fire. He goes back to bed. Later, the physicist wakes up and smells smoke. He opens his door and sees a fire in the hallway. He walks down the hall to a 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. Later, the mathematician wakes up and smells smoke. She goes to the hall, sees the fire and then the fire hose. She thinks for a moment and then exclaims, 'Ah, a solution exists!' and then goes back to bed. --- A physicist and a mathematician are in the faculty lounge having a cup of coffee when, for no apparent reason, the coffee machine bursts into flames. The physicist rushes over to the wall, grabs a fire extinguisher, and fights the fire successfully. The same time next week, the same pair are there drinking coffee and talking shop when the new coffee machine goes on fire. The mathematician stands up, fetches the fire extinguisher, and hands it to the physicist, thereby reducing the problem to one already solved... --- Alternate sequel: This time the physicist & mathematician are asked simply to fry an egg. The physicist calculates carefully and produces a carefully cooked egg; and the mathematician lights a fire in the corner, and says "I have reduced it to the previous problem." [I particularly like the "Aha! A solution exists!" part.] At 12:06 PM 2/26/2013, Dan Asimov wrote:
I just heard this one:
Which one is different:
A. An Applied Math Ph.D. B. A Pure Math Ph.D. C. A large pepperoni pizza D. A Statistics Ph.D.
Answer: