Two people choose a number between 0 and 1. Probability their sum is less than 1?

Two people choose a number between 0 and 1. Probability their sum is less than 1?

Approach: Area of the triangle in a 1x1 square.

0.5. Area of x+y < 1 is half the square.

Follow-up: Probability their product is less than 0.5?

Key concepts: continuous probability.