I have a glass of wine and a glass of water. Both glasses are of the same size, and contain the same amount of liquid.
Now I take one teaspoon from the glass of wine and put it in the glass of water. After mixing it with the teaspoon, I take a teaspoon from the glass of water and put it in the glass of wine.
Now, is the proportion of wine:water in the wine glass bigger, smaller or equal to the proportion of water:wine in the water glass?
While in class I saw the answer, but somehow managed to say it wrong. I don’t think drs. Hofman invented the problem, as Vladimir Arnold mentions this problem in an interview with S.H. Lui. In have very kind memories of mr. Hofman, he was always available for assistence or advice, and managed to challenge us without us realizing we were being challenged. He was also remarkable in another way: He managed to have three marriages days with the same woman. Thrice he proposed to her, thrice she accepted, but the first two times she said “no” on the morning of their marriage day, according to that I heard because she didnt have the courage to face that Big day.
Please try to solve the puzzles on your own. You are welcome to remark on the puzzles, and I love it when you comment variations, state wether they are too easy or too difficult, or simply your solution times. Please do not state the soultions – it spoils the fun for others. I usually make the solution available after one or two weeks through a link, which allows readers to check the solution without the temptation to scroll down a few lines before having a go at it themselves.
When you have solved this puzzle, you can check your solution here