

InterviewSolution
1. |
A card is drawn at random from a pack of 52 cards. Find the probability that the card drawn is:(i) a black king(ii) either a black card or a king(iii) black and a king(iv) a jack, queen or a king(v) neither a heart nor a king |
Answer» (i) A black king Total number of cards are 52 Number of black king cards = 2 Probability of getting black king cards is = Total number of black king cards/Total number of cards = 2/52 = 1/26 ∴ Probability of getting black king cards is 1/26 (ii) Either a black card or a king Total number of cards are 52 Number of either a black card or a king = 28 Probability of getting either a black card or a king is = Total number of either black or king card/Total number of cards = 28/52 = 7/13 ∴ Probability of getting either a black card or a king is 7/13 (iii) Black and a king Total number of cards are 52 Number of black and a king = 2 Probability of getting black and a king is = Total number of black and king card/Total number of cards = 2/52 = 1/26 ∴ Probability of getting black and a king is 1/26 (iv) a jack, queen or a king Total number of cards are 52 Number of a jack, queen or a king = 12 Probability of getting a jack, queen or a king is = Total number of jack, queen or king card/Total number of cards = 12/52 = 3/13 ∴ Probability of getting a jack, queen or a king is 3/13 (v) Neither a heart nor a king Total numbers of cards are 52 Total number of heart cards = 13 Probability of getting a heart is = Total number of hearts/Total number of cards = 13/52 = 1/4 Total number of king cards = 4 Probability of getting a king is = Total number of king card/Total number of cards = 4/52 = 1/13 Total probability of getting a heart and a king = 13/52 + 4/52 – 1/52 = (13+4-1)/52 = 16/52 = 4/13 ∴ Probability of getting neither a heart nor a king = 1 – 4/13 = (13-4)/13 = 9/13 |
|