And, Or, Not

Multiply, add, subtract from 1

An interactive lesson with 6 steps, about 5 minutes: you predict, drag and solve, with instant feedback on every answer. It runs in your browser and needs JavaScript.

What you’ll learn

• And (independent events): multiply. Not: 1 minus.
• Or: add, then subtract any overlap.
• “At least one” = 1 − P(none).

Steps

1. Double six
2. Three rules
3. The gambler’s question
4. Test it
5. Hearts or kings
6. Birthday surprise