How to Determine the Height of a Building
A mathematician, a physicist and an engineer are each given $50 to measure the height of a building.
The mathematician buys a ruler and a sextant, and by determining the angle subtended by the building a certain distance away from the base, he establishes the height of the building.
The physicist buys a heavy ball and a stopwatch, climbs to the top of the building and drops the ball. By measuring the time it takes to hit the bottom, he establishes the height of the building.
The engineer puts $40 into his pocket. By slipping the doorman the other ten and asking the building's height, he establishes the height of the building.