For the next couple of weeks we’ll be celebrating the life and interests of Martin Gardner, the American science and math writer who popularized the notion of recreational mathematics — math for fun. Fat Brain Toys is especially engaged in the life of Martin Gardner. As a company that believes that smart is good, and smart should be fun, we have been fans of Martin for a long time. In fact,we even run a local event that is part of a much larger national event called "Celebration of Mind". Take the time today to check out the national "Celebration of Mind" page here. Also, as part of special promotion we have posted Martin Gardner's favorite problem, "The Monkey and the Coconuts". The first person to solve the problem and give us the correct answer on our Celebration of Mind Nebraska facebook page will win a $25 Fat Brain Toys gift card. While you are there make sure and like our Celebration of Mind Nebraska page.
The Monkey and the Coconuts
Five men and a monkey were shipwrecked on a desert island, and they spent the first day gathering coconuts for food. Piled them all up together and then went to sleep for the night.
But when they were all asleep one man woke up, and he thought there might be a row about dividing the coconuts in the morning, so he decided to take his share. So he divided the coconuts into five piles. He had one coconut left over, and gave it to the monkey, and he hid his pile and put the rest back together.
By and by, the next man woke up and did the same thing. And he had one left over and he gave it to the monkey. And all five of the men did the same thing, one after the other; each one taking the fifth of the coconuts in the pile when he woke up, and each one having one left over for the monkey. And in the morning they divided what coconuts were left, and they came out in five equal shares. Of course each one must have known that there were coconuts missing; but each one was guilty as the others, so they didn’t say anything. How many coconuts were there in the beginning?
Mr. Gardner also offers his own simplified version of the problem:
Three sailors come upon a pile of coconuts. The first sailor takes half of them plus half a coconut. The second sailor takes half of what is left, plus half a coconut. The third sailor also takes half of what remains, plus half a coconut. Left over is exactly one coconut, which they toss to the monkey. How many coconuts were in the original pile? If you arm yourself with 20 matches, you will have ample material for a trial-and-error solution.