A ping pong ball is drawn at random from an urn consisting of balls numbered 2 through 10. A player wins 1 dollar if the number on the ball is odd and loses 1 dollar if the number is even. What is the expected value of his winnings?

A card is randomly selected from a 52 card deck. Find the probability that the card is a king or a diamond?

You pay $20 to enter a raffle.  The first ticket drawn wins $1036, the second ticket drawn wins $477, the third through fifth win $186, and the sixth through tenth win $49.  Suppose 2345 tickets were sold.  What is the expected earning on your ticket?

At bedtime, you read three books to your kids, Walker, Michael, and Luke. Together, they have 32 books. If you decide to randomly choose three books, what is the probability that the three you choose will consist of each of their favorite books? Assume they have different favorites. Express your answer as a fraction in lowest terms or a decimal rounded to the nearest millionth.

An urn contains 10 red marbles, 7 white marbles, and 8 blue marbles marbles. A child randomly selects three (without replacement) from the urn. Round to four decimal places. a. Find the probability all three marbles are the same color. b. Find the probability that none of the three marbles are white.

A magazine subscription service is having a contest in which the prize is 180000. If the company receives 3 million entries, which is the expection of the contest?

A five-card poker hand is dealt from a standard deck of cards.  Find the probability of getting two pair.