Hello, Volga!

Here is part of the solution . . .

Consider three mutually exclusive and exhaustive events and where:

. .

. .

. . .

What condition on must hold?

You are correct.

"Mutually exclusive" and "mutually exhaustive" means the sets have

. . no overlap, and together they "take up" the entire sample space.

The Venn diagram looks like this:

Code:* - - - - - - - * | | * A0 * | * * | | * * | | * * | | A1 * A2 | | | | * - - - * - - - *

Let represent theof their respective regions in the unit square.areas

. . . . .

Therefore: .