Statistics

A physics exam consists of 9 multiple choice questions and 6 open-ended problems in which all work must be shown. If an examinee must answer 7 of the multiple choice question and 3 of the open ended problems, in how many ways can the questions and problems be chosen?

It is known that cars arrive at a drive-thru at a rate of three cars per minute between 12 noon and 1:00 pm. Assuming the number of cars that arrive in any time interval has a Poisson distribution, what is the probability that exactly 9 cars arrive 12:10 and 12:15?

A professor wants to arrange his books on a shelf. He has 30 books and only space on the shelf for 20 of them. How many different 20-book arrangements can be make using 30 books? This is an example of a problem that can be solved using which method?

On a particular night, 50% of a group of people polled says that they are going to watch the hockey game and 26% says they are going to watch both the hockey game and the news. If 87% say they are going to watch at least one program, what percentage of these people say they are going to watch the news?

In a playoff series, the probability that Team A wins over Team B is 3/5, and the probability that Team C wins over Team D is 4/7. If the probabilities are independent, the probability that Team A wins and Team C loses is

The number of customers entering a bank per minute is a Poisson random variable with a mean of 3.5 customers per minute. What is the probability that more than three customers enter the bank in a minute?

The probability that a certain machine will produce a defective item is 0.20. If a random sample of 6 items is taken, what is the probability that there will be 5 or more defectives in the sample?

According to a survey, 75% of all customers will return to the same grocery store. Suppose eight customers are selected at random, what is the probability that exactly five of the customers will return?

A bag contains 2 red, 3 green and 2 blue balls. Two balls are drawn at random. What is the probability that none of the balls drawn are blue?

Two cards are drawn without replacement from a deck of 52 cards. the probability of the first card being red face and the second card being a club is