By Muriel Bristol (Transcriber) | September 18, 2018
The eighth-century English scholar Alcuin devised the following puzzle for the Emperor Charlemagne.
A traveler comes to a riverbank with a wolf, a goat and a head of cabbage. To his chagrin, he notes that there is only one boat for crossing over, which can carry no more than two passengers — the traveler and either one of the two animals or the cabbage. As the traveler knows, if left alone together, the goat will eat the cabbage and the wolf will eat the goat. The wolf does not eat cabbage. How does the traveler transport his animals and his cabbage to the other side intact in a minimum number of back-and-forth trips?
[Answer to Puzzle #4 to follow in the next Puzzle]
Solution to Puzzle #3: Lightbulbs in the Attic
Turn on a switch and leave it on for several minutes. Then turn it off and turn on a second switch. Go to the attic. One light is burning: the one that switched on second and is still active. Feel the two bulbs that are not burning. One of them is still warm from having been switched on by the first switch for several minutes. By a process of elimination, the remaining bulb (the cool one) is activated by the third switch that was never used.