

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 numbers of cards are 52 Number of black king cards = 2 Probability of getting black king cards is = \(\frac{Total\,number\,of\,blackking\,cards}{Total\,number\,of\,cards}\) = \(\frac{2}{52}\) = \(\frac{1}{26}\) Therefore Probability of getting black king cards is = \(\frac{1}{26}\) (ii) either a black card or a king Total numbers 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 = \(\frac{Total\,number\,of\,blackking\,cards}{Total\,number\,of\,cards}\) =\(\frac{28}{52}\) = \(\frac{7}{13}\) Therefore Probability of getting either a black card or a king is = \(\frac{7}{13}\) (iii) black and a king Total numbers of cards are 52 Number of black and a king = 2 Probability of getting black and a king is = \(\frac{Total\,number\,of\,blackking\,cards}{Total\,number\,of\,cards}\) = \(\frac{2}{52}\) = \(\frac{1}{26}\) Therefore Probability of getting black and a king is = \(\frac{1}{26}\) (iv) a jack, queen or a king Total numbers of cards are 52 Number of a jack, queen or a king = 12 Probability of getting a jack, queen or a king is = \(\frac{Total\,number\,of\,blackking\,cards}{Total\,number\,of\,cards}\) = \(\frac{12}{52}\) = \(\frac{3}{13}\) Therefore Probability of getting a jack, queen or a king is = \(\frac{3}{13}\) (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 = \(\frac{Total\,number\,of\,blackking\,cards}{Total\,number\,of\,cards}\) = \(\frac{4}{52}\) = \(\frac{1}{13}\) Total probability of getting a heart and a king = \(\frac{13}{52}+\frac{4}{52}-\frac{1}{52}=\frac{16}{52}=\frac{4}{13}\) Therefore probability of getting neither a heart nor a king = \(1-\frac{4}{13}=\frac{9}{13}\) |
|