I remember reading Gardner’s The Colossal Book of Mathematics in middle school. That and Theoni Pappas’s The Joy of Mathematics were the staples of my mathematical education during those years. I was introduced to Conway’s Game of Life, basic knot theory, and not to mention an array of cool puzzles. Because of the impact that one book had on my perception of math (and partly the reason why I’m here now), I wanted to write a bit about some puzzles by Gardner I particularly liked. I won’t provide answers but a quick Googling should be sufficient to find them. But I do recommend working through them first.
Also, an explanation as to why I have not been blogging recently. I am currently in the middle of a rigorous grad school application cycle. If it hasn’t been clear from this blog, I’m applying to grad school so I can continue to explore and learn and do what I love.
Now, onward to puzzles:
And finally, the first puzzle in The Colossal Book of Mathematics which I spent quite a bit of time on back in the day:
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?
Images and description courtesy of puzzles.com.