Intersection: Coins

P(A ∩ B) - both conditions satisfied

Understanding "AND" (Intersection)

What does "AND" mean in probability?

When we say "A AND B", we mean both events must occur. In probability notation, this is written as P(A ∩ B) — the intersection of A and B.

How is "AND" different from "OR"?

Think of it as a filter: "AND" is more restrictive, so fewer outcomes satisfy it.

For independent events (like separate coin flips):

When events don't affect each other, we can multiply their probabilities:

Green = Both heads

Count favorable outcomes

Only HH satisfies "both heads"

Calculate probability

Result:

For independent events (like separate coin flips):