Numbers & chance

Chance & probability

Run it again and again, and count what luck really does. 9 works

Monty Hall Problem

One of three doors hides a prize. After you pick, is it better to switch?
Birthday Paradox

How big must a group be to have a shared birthday? Try different sizes.
Galton Board

A ball goes left or right at every peg by chance. Watch what shape the pile of balls makes.
Coin Flips and the Law of Large Numbers

The share of heads settles near one half, yet the gap between heads and tails keeps growing.
Buffon's Needle

Drop needles on a lined floor and watch pi appear.
Tests and Base Rates

A positive test does not always mean you are sick. See why with dots.
The Drunkard’s Walk

Dots take random steps. See how far from the start they spread out.
Secretary Problem

When should you stop looking and choose?
The Missing Failures: Survivorship Bias

You only see planes that made it back. Where do you add armor? The ones that never returned hold the answer.