This is a fun logic game. It’s an easy one, too. You see six pairs of horse’s legs under a fence, so how many horses are there? Each horse has the normal number of legs, so it’s not a trick question. You have to figure out the answer, which you don’t know, from the information you do know.
Logic games go back a long way. In ancient Greece, the favorite logic game was debate, and Aristotle wrote up the rules for it. In the 19th century, Lewis Carroll, the author of Alice’s Adventures in Wonderland, invented the logic puzzle. One of his puzzles was “No fat creatures run well, and some greyhounds run well. What can you conclude?” The answer is “Some greyhounds are not fat.”
This logic game about the six pairs of horse’s legs requires deduction.
Deduction is reasoning from known facts and drawing a conclusion. We know there are six pairs of legs, so that’s a total of 12 legs. We know that horses have 4 legs each. So 12 legs divided by 4 legs each leaves 3. There are 3 horses.
Another way of looking at it is that there are 6 pairs of legs and each horse has 2 pairs of legs, so 6 divided by 2 is 3. Again, there are 3 horses.
Fun, isn’t it? Now you feel like Mr. Spock!