Combining Expected Value

You roll a standard die. You win $12 if you roll a six, $6 if you roll a one, and $0 if you roll anything else. What is the expected value of a single roll?

• $3

• $18

• $9

• $2

Find the expected value.

• 0.4

• 0.6

• 0

• 1.1

If the expected value is positive, are you expected to win?

• yes

• no

You spin each spinner once. You get $50 if you spin a 2 and a vowel. You get $25 if you spin a 2 and a consonant. You get $5 if you spin a 1 and a vowel. Everything else earns $0. What is the expected value of this game?

• $80

• $8.75

• $10.25

• $12.50

You are going to pick a marble from the container, put it back, and take another. If you get two yellow, you win $200. If you get one yellow on either pick, you get $50. If you pick two red, you get $100. Anything else earns $0. What is the expected value of this game?

• $60

• $33.33

• $44.33

• $20

You roll two fair dice. If they land with a sum of 7, you get $10. If they land with a sum of 6 or 8, you get $5. Everything else earns $0. Which of the following would be the most reasonable amount to pay to play this game?

• $2

• $5

• $8

• $10

Your business is looking into looking into three contracting firms. Based on previous research, there is a 75% chance that company 1 will earn you $40,000. There is a 45% chance that company 2 will earn you $60,000. Company 3 has a 30% chance of earning you $80,000. It costs $20,000 to draw up legal paperwork for each company. How much profit or loss would you expect after this deal is done?

• $81,000 profit

• $81,000 loss

• $21,000 profit

• $21,000 loss

Your friend shuffles a standard deck of cards and says to pick one. If you pick a face card (Jack, Queen, King of each suit) your friend will give you $10. If you pick anything else, you owe your friend $5. How much should you expect to win or lose by playing this game?

• Lose $6.15

• Win $6.15

• Lose $1.50

• Win $1.50

Two new movies are being released. According to market research, the first movie has an 85% chance of making $32,000,000. The second movie has a 33% chance of making $120,000,000. What is the expected earnings for these two movies?

• Around $15 million

• Around $20 million

• Around $30 million

• Around $60 million

• Yes, because all of the probabilities are between 0 and 1 inclusive and the sum of all the probabilities is 1.
• No, all probabilities are not be between 0 and 1 inclusive
• No, the sum of all the probabilities is not 1.
• Yes, because the distribution is symmetric