You have two ropes that each burn in 1 hour but not at a uniform rate. How can you measure 45 minutes?

How can you make 6 equal triangles from 4 match sticks?

How many digits are in the number 125^100?

The YouTube channel and blog Mind Your Decisions has millions of views for math videos and posts. This ebook contains 70 puzzles divided into easy, medium, and hard puzzles in the areas of geometry, logic, number theory, and probability.