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In his marvelous Idea Book, Fredrik Haren tells the story of a teacher who wanted her students to measure the height of a house using only a barometer. The “correct” answer she was looking for was that they should use the barometer to measure the difference in air pressure at the ground and the top of the house, and utilize that data to calculate the height of the house. One enterprising student, however, came up with some other unique yet valid solutions to this problem – which the teacher did not accept. This anecodote reminds us that there is more than one correct answer for any problem.

In his marvelous Idea Book, Fredrik Härén tells the story of a teacher who wanted her students to measure the height of a house using only a barometer. The “correct” answer she was looking for was that they should use the barometer to measure the difference in air pressure at the ground and the top of the house, and utilize that data to calculate the height of the house. One enterprising student, however, came up with some other unique yet valid solutions to this problem – which the teacher did not accept. These answers included:

  • Attach a piece of string to the barometer and lower it from the roof of the house until it reaches the ground, then measure the length of the string.
  • Climb up onto the roof of the house, drop the barometer and measure the time it takes to reach the ground. Use this time interval and known values of gravity and acceleration to calculate the height of the house.
  • Climb up the stairs in the house and, on the way up, take measurements against the wall, using the barometer as a measuring stick. Upon reaching the top, multiply the length of the barometer by the number of times it was used as a measure to determine the height of the house.

The last solution the creative student thought of isn’t very scientific, but it is definitely quite funny: The student, by this time frustrated with his teacher’s narrow-mindedness, said he would go to the house, knock on the door and say to the occupant, “If you don’t tell me how tall your house is, I’ll beat you to death with my barometer!”

Most of us were taught by our school teachers that for each and every problem, there is one correct answer. This memorable anecdote demonstrates that this simply isn’t true. For most problems, there are many ways to solve them; some solutions are more effective and others are less effective. It’s to our advantage to think of many potential solutions and then select the one that does the best job of solving the problem.