Standard 52-card deck: What is the probability that a card drawn at random is either a king or a spade?

Introduction / Context:
We need P(King ∪ Spade) from a standard deck. Use inclusion–exclusion to avoid double counting the king of spades.

Given Data / Assumptions:
There are 4 kings total and 13 spades total; the king of spades is in both sets.

Concept / Approach:
P(A ∪ B) = P(A) + P(B) − P(A ∩ B).

Step-by-Step Solution:

Verification / Alternative check:
Counting: favorable cards are 3 non-spade kings + 13 spades = 16 distinct cards.

Why Other Options Are Wrong:
17/52 double-counts; 13/52 is spades only; 3/13 undercounts.

Common Pitfalls:
Forgetting to subtract the overlap (king of spades).

Final Answer:
4/13