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A card is drawn from a well-shuffled deck of 52 cards. What is the probability that it is a King or a Heart?
4/13
16/52
17/52
1/4
4/13
Count total favorable outcomes: 4 Kings + 13 Hearts - 1 (the King of Hearts counted twice) = 16. Divide by 52 to get 16/52 = 4/13.
A deck has 52 cards. We need to find the probability of drawing a King (K) or a Heart (H).
P(AтИкB)=P(A)+P(B)тИТP(AтИйB)
Count total favorable outcomes: 4 Kings + 13 Hearts - 1 (the King of Hearts counted twice) = 16. Divide by 52 to get 16/52 = 4/13.
Students often add 4 Kings and 13 Hearts to get 17 outcomes, forgetting that the King of Hearts is a member of both groups and is being counted twice.
Identify individual probabilities
There are 4 Kings in a deck and 13 Hearts. The probability of picking a King is P(K)=4/52 and a Heart is P(H)=13/52.
P(K)=524тАЛ,P(H)=5213тАЛ
Identify the intersection
There is exactly 1 card that is both a King and a Heart (the King of Hearts).
P(KтИйH)=521тАЛ
Apply Addition Theorem
Combine the probabilities while subtracting the overlap to avoid double counting.
P(KтИкH)=524тАЛ+5213тАЛтИТ521тАЛ
Final Calculation
Sum the numerators: 4+13тИТ1=16. Divide by the denominator 52 and simplify the fraction.
5216тАЛ=134тАЛ
A is correct because the application of the inclusion-exclusion principle results in 16/52, which simplifies to 4/13.
This principle of P(AтИкB)=P(A)+P(B)тИТP(AтИйB) is the foundation for solving Set Theory problems in Data Interpretation.