In 1990, a reader asked Marilyn vos Savant a deceptively simple probability question in her newspaper column. Her answer — that you should switch doors in the Monty Hall problem — sparked outrage ...

The problem Litt posted was: 'Suppose you have a urn containing 100 balls, n of which are red and 100-n are green, where n is uniformly distributed between 0 and 100. You randomly draw a ball from the ...

An animated guide to probability explains how to express probability as fractions and percentages based on the ratio of the number of ways an outcome can happen and the total number of outcomes.