Here are some more lateral thinking puzzles:
"I don't know," replied Bob, "but I'm willing to give ten-to-one odds that I can name one of the three that died on that date."
Assuming that Bob knows the names of the first five presidents of the United States but has no knowledge of the dates on which any of the first five presidents died, was he justified in offering such odds? If so, why?
"I see," said the prisoner. "Then if I try every possible number, I'm sure to hit the right one."
"True," said the warden, "but even if you were able to change the numbers at the rate of one per second without resting, it would take you a hundred years to hit the right combination. However, you could try numbers at random and have a chance of choosing the right one. Or, you could look for the clue that we always provide."
"What sort of clue?"
"It could be just about anything. For example, once a prisoner was put in an escape-proof cell and told that he would be pardoned if he could break out. He was also given permission to keep any plants he wished in his cell."
"What happened to him?"
The warden laughed. "After over two years, he finally realized that some words may have more than one meaning. He requested a poison ivy plant. Soon after receiving it, he broke out—in a rash. Of course, he then received his pardon."
The warden unlocked the cell and ushered the prisoner in. "Your cell contains a calculator, pencils, and paper. Good luck."
Left alone, the prisoner tried a few combinations on the lock without success. What could the clue be? A thought struck him. It seemed worth a try. He made a few calculations, and then set up a number on the lock. The cell door opened and the prisoner went out, after serving less than half an hour of his sentence. What was the clue?
The answers can be found at Lateral Thinking Puzzles #5 Answers. Need a hint?
If you enjoyed these puzzles, there are four other pages of lateral thinking puzzles on this site: See lateral thinking puzzles page 1, page 2, page 3, and page 4.