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Category Archives: Riddles
Ehud Friedgut: How many cubes of 2×2×2 fit into a box of size 8×4×3? (TYI 49)
This blog post is kindly written by Ehud Friedgut. My daughter, Shiri, who’s in seventh grade, had the following question in a math exam: How many cubes of 2×2×2 fit into a box of size 8×4×3? Shiri divided the volumes, … Continue reading
Posted in Geometry, Riddles, Test your intuition
Tagged Alef's corner, Ehud Friedgut, Shiri Friedgut, Test your intuition
6 Comments
Cheerful Test Your Intuition (#45): Survey About Sisters and Brothers
You survey many many school children and ask each one: Do you have more brothers than sisters? or more sisters than brothers? or the same number? Then you separate the boys’s answers from the girls’s answers Which of the following … Continue reading
Posted in Combinatorics, Probability, Riddles, Statistics, Test your intuition
Tagged Test your intuition
7 Comments
TYI38 Lior Kalai: Monty Hall Meets Survivor
For breaking news, scroll down. Lior Kalai: Survivor Meets the Monty Hall Puzzle We start with the classical question and go on with a new version contributed by my son Lior. Update: A few brief comments on the original problem … Continue reading
Posted in personal, Probability, Riddles, Test your intuition, Women in science
Tagged Karen Uhlenbeck, Lior Kalai, Monty Hall problem, Survivor
4 Comments
In how many ways you can chose a committee of three students from a class of ten students?
The renewed interest in this old post, reminded me of a more recent event: Question: In how many ways you can chose a committee of three students from a class of ten students? My expected answer: which is 120. Alternative … Continue reading
Posted in Mathematics to the rescue, Riddles, Teaching
1 Comment
The Mystery Beeping Riddle
We came back from the airport with our daughter who has just landed after a four-month trip to India. The car was making a strange beep every so often. Maybe it is an indicator signal that should have … Continue reading
Posted in Mathematics to the rescue, Rationality, Riddles
12 Comments
Greg’s Dinosaurs Riddle
The two-riddles post was a success, and while corresponding with Greg Kuperberg he had a riddle for me about dinosaurs, and he agreed I will share it with you. Right before the Chixculub asteroid hit the earth, there were a … Continue reading
Two Math Riddles
Usually I am not particularly good at telling math riddles or solving them, and I was not planning on presenting math riddles here. But these days, when mathematical blogs break new ground and enter uncharted territories, let me make an exception and tell you … Continue reading
Combinatorics and more 