Probability

myteapot172000

2011-04-17 12:42 am

1.
The probability of David passes each Mathematics quiz is 0.8.If there are 5
quizzesin this term,Find the probability that he passes at least one quiz.

2.
Three indeppendent companies A ,B and C will hold their annual dinners in any one of the months.Find the probability that the three annual dinners are held in the same month.

3.
Mary has 5 differentnecklaces and 7 different pairs of earrings and always wears one of each when she goes out.Assume that she chooses her
accessories at radom every day.Find the probabilities that(a) she wears a particular combination on a certain day(b)she wears a particular combination on two consecutive day.

回答 (1)

myisland8132

2011-04-17 1:24 am

✔ 最佳答案

1 P(passes at least one quiz)= 1 - (0.2)^5= 0.999682 A can be set at any months and then B, C follow ASo, P(three annual dinners are held in the same month)= (1/12)(1/12)= 1/1443(a) (1/5)(1/7) = 1/35(b) (1/35)(1/35) = 1/1225

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