Question

h) Eating an extu cigarettes 2, A survey found that 68% of book buyers are 40 or older. If two book buyers are selected at random, find the probability that both are 40 or older. 3. Seventy-three percent of diners favor the practice of tipping to reward good service. If five restaurant customers are selected at random, what is the probability that all five are in favor of tipping? 4. Cards: If 2 cards are selected from a standard deck of 52 cards without replacement, find these probabilities. a) Both are spades b) Both are the same suit. c) Both are kings. 5. Flashlight Batteries A flashlight has 6 batteries, 2 of which are defective. If 2 are selected at random without replacement, find the probability that both are defective. 6. Customer Purchases In a department store there are 120 customers, 90 of whom will buy at least 1 item. If customers are selected at random, one by one, find the probability that all will buy least 1 item. 5 7. Drawing Cards Three cards are drawn from a deck without replacement. Find these probabilities. a) All are jacks. b) All are clubs. c) All are red cards.

Answer 1

Solution:-

2) Probability that both are 40 or older = 0.68 x 0.68 = = 0.4624

3) P(X = 5) = 0.73^5 = 0.2073

4) a) P(Both Spades) = (13/52)(12/51) = 156/2652 = 1/17
b) P(Both same suit) = 12/51
c) P(both are kings) = 8C2/52C2 = (8*7)/(52*51) = 0.0211

5) P(select 2 defective) = 2C2/6C2 = 1/15

6) P(5 buy at least one) = 1 - P(none of 5 buy at least one) = 1 - 30C5/120C5 = 0.999252

7) a) P(all are jacks) = 4/52 * 3/51 * 2/50 = 1/5525
b) P(all are clubs) = 13/52 * 12/51 * 11/50 = 11/850
c) P(all are red card ) = 26/52 * 25/51 * 24/50 = 2/17