119k views
3 votes
You pay $3.00 to play. The dealer deals you one card. If it is a spade, you get $10. If it is anything else, you lose your money. What is the expected value? Round to 2 decimal places.

A. -$3.00
B. -$1.50
C. $0.33
D. $0.50
E. $7.00

User Adjuremods
by
7.0k points

1 Answer

3 votes

Final answer:

The expected value of the game is $0.25, which means option D ($0.50) is the closest answer. The expected value was calculated considering the probabilities of winning and losing, and the respective payouts and costs.

Step-by-step explanation:

The question asks about the expected value of a game where you pay $3.00 to play, and the dealer deals you one card. The payout is $10 if the card is a spade; otherwise, you lose the $3.00 paid to play the game. A standard deck of cards contains 52 cards with 13 cards in each suit, including the spades.

To calculate the expected value, we consider two scenarios. The probability of getting a spade (winning scenario) is 13/52 (since there are 13 spades in a deck of 52 cards). The probability of not getting a spade (losing scenario) is 39/52, as there are 39 cards that are not spades in a standard deck.

The expected value (EV) can be calculated using the formula:

EV = (Probability of winning)×(Winning amount) + (Probability of losing)×(Losing amount)

Thus:

EV = (13/52)×($10) + (39/52)×(-$3)

EV = 0.25×$10 - 0.75×$3

EV = $2.50 - $2.25

EV = $0.25

Therefore, the expected value of playing this game is $0.25, meaning option D ($0.50) is the closest answer after rounding.

User Rajesh Dalsaniya
by
7.2k points