Question

The game of roulette is popular in many casinos around the world. In Las Vegas, a typical roulette wheel has the numbers 1–36 in slots on the wheel. Half of these slots are red, and the other half are black. In the United States, the roulette wheel typically also has the numbers 0 (zero) and 00 (double zero), and both of these are on the wheel in green slots. Thus, there are 38 slots on the wheel. The dealer spins the wheel and sends a small ball in the opposite direction of the spinning wheel. As the wheel slows, the ball falls into one of the slots, and that is the winning number and color. One of the bets available is simply red or black, for which the odds are 1 to 1. If the player bets on either red or black, and that happens to be the winning color, the player wins the amount of her bet. For example, if the player bets $5 on red and wins, she is paid $5 and she still has her original bet. On the other hand, if the winning color is black or green when the player bets red, the player loses the entire bet.

(a) What is the probability that a player who bets red will win the bet?

(b) If a player bets $10 on red every time the game is played, what is the expected monetary value (expected win)?

(c) In Europe, there is usually no 00 on the wheel, just the 0. With this type of game, what is the probability that a player who bets red will win the bet? If a player bets $10 on red every time in this game (with no 00), what is the expected monetary value?

(d) Since the expected profit (win) in a roulette game is negative, why would a rational person play the game?

Answer 1

If the game is played in US it has routtle wheel colours as 18 red 18 black and 2 green so probality of selecting red colour is 18÷38.

Expected value is the mean of values and calculated by summation of product of expected values and it's probability.

So although having negative expected profit in a roulette game people believes in their luck that out of many chances they have the chance to win profits.