From a standard 52-card deck, what is the probability that a randomly drawn card is a diamond or a king?
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A4/52
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B4/13
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C1/52
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D2/13
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ENone of these
Answer
Correct Answer: 4/13
Explanation
Introduction / Context:We compute a simple union of two card events: “diamond” or “king”. Since one card (king of diamonds) lies in both sets, inclusion–exclusion is needed to avoid double-counting.
Given Data / Assumptions:
- Diamonds = 13 cards.
- Kings = 4 cards.
- Overlap = 1 card (king of diamonds).
- Total cards = 52.
Concept / Approach:P(diamond ∪ king) = (13 + 4 − 1)/52 = 16/52. Reduce the fraction to simplest terms.
Step-by-Step Solution:
Favorable = 16.Probability = 16/52 = 4/13.Verification / Alternative check:Complementary event is “not diamond and not king” = 39/52; thus union is 1 − 39/52 = 13/52? Careful: “not diamond and not king” equals 52 − (diamonds ∪ kings) = 36; hence union is 16/52 = 4/13, matching above.
Why Other Options Are Wrong:4/52 is only diamonds OR only kings if miscounted; 2/13 undercounts; 1/52 is just a single card.
Common Pitfalls:Double-counting the king of diamonds by simply adding 13 + 4 without subtracting the overlap.
Final Answer:4/13