InterviewSolution
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One card is drawn from a well shuffled deck of 52 cards. If each outcome is equally likely, calculate the probability that the card will be (i) a diamond (ii) not an ace (iii) a black card (i.e., a club or a spade) (iv) not a diamond (v) not a black card. |
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Answer» When a card is drawn from a well shuffled deck of 52 cards, the number of possible outcomes is 52. (i) Let A : ‘the card drawn is a diamond’ Clearly the number of elements in set A is 13. ∵ n(S) = 52 and n(A) = 13 ∴ P(A) = n(A)/n(S) = 13/52 = 1/4 (ii) Let B: ‘card drawn is an ace’. B’: ‘card drawn is not an ace’ we have, n(13) = 4,n(S)= 52 ∴ P(B) = n(B)/n(S) = 4/52 = 1/13 Required probability =P(B’) We have P(B') = 1 - P(B) = 1 - 1/13 = 12/13 (iii) Let C : ‘card drawn is black card’. ∴ Number of elements in set C = 26 i.e., n(C) =26 ∴ P(C) = n(C)/n(S) = 26/52 = 1/2 (iv) Let A: ‘card drawn is a diamond’ ∴ A’: card drawn is not a diamond’ We have n(A) = 13, n(S) = 52 ∴ P(A) = 13/52 = 1/4 we have P(A') = 1 - P(A) = 1 - 1/4 = 3/4 (v) We have p(C) = 1/2 (from (iii)) ∴ P(C') = 1 - P(C) = 1 - 1/2 = 1/2 |
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