Updated: 2023-12-27 17:17:30
One of the perks of being a teacher is receiving congratulations not only from family and friends, but also from students. By the way, I do not like physical gifts — I prefer just congratulations. Luckily, MIT has a policy that doesn’t allow accepting gifts of any monetary value from minors and their parents. Thus, […]
Updated: 2023-12-22 18:38:58
Puzzle. There are 100 cards with integers from 1 to 100. You have three possible scenarios: you pick 18, 19, or 20 cards at random. For each scenario, you need to estimate the probability that the sum of the cards is even. You do not need to do the exact calculation; you just need to […]
Updated: 2023-12-20 18:11:17
I like including warm-up puzzles with every homework. Puzzle. Farmer Giles has four sheep. One day, he notices that they are all standing the same distance away from each other. How can this be so? The expected answer: The configuration is impossible in 2D. So, one of the sheep is on a hill or in […]
Updated: 2023-12-14 16:51:19
I loved coin puzzles, but after several research projects related to those shiny discs, I got tired of them. The fatigue was temporary, as confirmed by the following Facebook puzzle that reignited my interest. Puzzle. There are 30 coins in a circle that look the same. However, 20 of them are fake, and the rest […]
Updated: 2023-12-13 15:33:57
My PRIMES STEP program consists of two groups of ten students each: the senior group and the junior group. The senior group is usually stronger, and they were especially productive last academic year. We wrote four papers, which I described in the post EvenQuads at PRIMES STEP. The junior group wrote one paper related to […]
