Tanya Khovanova's Math Blog

Here is the famous Sleeping Beauty problem.

Puzzle. Sleeping Beauty agrees to take part in an experiment. On Sunday, she is put to sleep, and a fair coin is tossed. If it lands heads, she is awakened on Monday only. If it lands tails, she is awakened on both Monday and Tuesday. After each awakening, she is put back to sleep and given a drug that er...

I have a vague memory from a long time ago. Someone told me that after wars, nature wants to replenish the killed men, and the proportion of boys among babies increases. I recently remembered this claim and looked it up. Yes, the statistical part is real: during and right after both of the World Wars, the proportion of boys increased. This effect even has its own name: the

In 2016, I posted a cute puzzle, An Asteroid Walk, on my blog. Here it is.

Puzzle. Seven astronauts landed on a small spherical asteroid. They wanted to explore it and walked in different directions starting from the same location. Al...

I used to write a review and list math-related puzzles for each MIT Mystery Hunt. Recently, my team, Death and Mayhem, started a new tradition of adding descriptions to the puzzle list. This makes it easy to find puzzles related to math. Nowadays AI can also help. So I plan to stop writing hunt reviews.

So consider this a farewell to my annual MIT Mystery Hunt revie...

I have finally become a queen — though only in a research paper. In Immensely Questionable Tests, I am Queen Tanya, and my ten PRIMES STEP student coauthors are my sages.

The project began with a probability puzzle from Mathematical Puzzles and Curiosities, m...