Probability of drawing a spade or a king from a deck?

Probability of drawing a spade or a king from a deck?

Approach: P(A) + P(B) - P(A and B).

4/13. (13/52) + (4/52) - (1/52) = 16/52 = 4/13.

Follow-up: Probability of heart or diamond?

Key concepts: inclusion-exclusion.