FUNNIEST Heads Up Challenge

Samins Challenge

The Challenges Ahead

Helium Balloon Challenge

The production of Humulilm was a challenge as:

Introduction|Thinking About Challenges|Different Contexts, Different Challenges|Summary

There are two coins, one unbiased with probability 1/2 or getting heads and the other one is biased with probability 3/4 of getting heads. A coin is selected at random and tossed. It shows heads up. Then the probability that the unbiased coin was selected is