# Math question (Probability)?

1. Three classes 4A, 4B and 4C attend a quiz contest. 3 representatives from each class will answer 10 questions. If any representative answers a question correctly, the class will get 10 marks; otherwise the class will get no marks. The probabilities that each of the representatives of 4C can answer a question... 顯示更多 1. Three classes 4A, 4B and 4C attend a quiz contest. 3 representatives from each class will answer 10 questions. If any representative answers a question correctly, the class will get 10 marks; otherwise the class will get no marks. The probabilities that each of the representatives of 4C can answer a question correctly are 0.6, 0.8 and 0.75 respectively.

P(4C will get 10 marks after answering a question) = 0.98

If 4A and 4B got 80 and 60 marls respectively after answering the questions, find the probability that only 4C will win the contest, cor. to 4 decimal places.

2. If Kenny passes a mock exam, the probability that he passes the public exam is 0.8.If he fails the mock exam, the probability that he fails the public exam is 0.6. If the probability that Kenny passes the mock exam is 0.7, the probability that she passes the public exam is?