   1. Chapter 13 Class 12 Probability
2. Serial order wise
3. Examples

Transcript

Example 9 Three cards are drawn successively, without replacement from a pack of 52 well shuffled cards. What is the probability that first two cards are kings and the third card drawn is an ace? Probability first two cards are king & third drawn is ace = Probability first card is king Probability second card is king , if first card is king Probability third card is ace, if first two are kings So, P(KKA) = P(K) P(K|K) P(A|KK) Now, P(K) = Probability that first card is king Number of kings in a pack of 52 cards = 4 P(K) = = 4 52 = 1 13 P(K|K) = Probability that the second card drawn is king, if the first card drawn has a king If first card drawn has king, Total number of kings left in the pack = 3 & Total number of cards in the pack = 51 P(K|K) = 3 51 = 1 17 P(A|KK) = Probability that the third card is an ace, given first two cards were kings If first two card drawn were kings, Total number of aces left in the pack = 4 & Total number of cards in the pack = 50 P(A|KK) = 4 50 = 2 25 Now, P(KKA) = P(K) P(K|K) P(A|KK) = = P(KKA) = 2 5525

Examples 