A roulette wheel has 38 slots, 18 are red, 18 are black, and 2 are green.You play five games and always bet on red. a) How many games can you expect to win? b) What is the probability that you will win all five games? c) If you win three or more games, you make a profit. If you win two or fewer games, you lose money. What is the probability that you will win no more than two games?

Respuesta :

Answer:

a) 2.35 games.

b) Therefore, the probability is P=0.0229.

c) Therefore, the probability is P=0.71.

Step-by-step explanation:

We know that a roulette wheel has 38 slots, 18 are red, 18 are black, and 2 are green.You play five games and always bet on red.

Therefore, we have

[tex]p=\frac{18}{38}=0.47\\\\q=\frac{20}{38}=0.53\\[/tex]

a) We  can you expect to win 5·0.47= 2.35 games.

b) We calculate the  probability that you will win all five games.

[tex]P=C_5^5\cdot p^5\cdot q^0\\\\P=1\cdot 0.47^5 \cdot 0.53^0\\\\P=0.0229[/tex]

Therefore, the probability is P=0.0229.

c)  We calculate the probability that you will win  three or more games.

[tex]P=1-C_2^5\cdot 0.47^3\cdot 0.53^2\\\\P=1-10\cdot 0.47^3\cdot 0.53^2\\\\P=1-0.29\\\\P=0.71[/tex]

Therefore, the probability is P=0.71.

Using the binomial distribution, it is found that:

a) You expect to win 2.4 games.

b) 0.0239 = 2.39% probability that you will win all five games.

c) 0.5492 = 54.92% probability that you will win no more than two games.

For each game, there are only two possible outcomes. Either you win, or you lose. The probability of winning a game is independent of any other game, which means that the binomial distribution is used to solve this question.

Binomial probability distribution

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]

  • x is the number of successes.
  • n is the number of trials.
  • p is the probability of a success on a single trial.

In this problem:

  • Five games, thus [tex]n = 5[/tex].
  • 18 out of 38 spots are red, thus [tex]p = \frac{18}{38} = 0.4737[/tex].

Item a:

The expected value is:

[tex]E(X) = np = 5(0.4737) = 2.4[/tex]

You expect to win 2.4 games.

Item b:

This probability is P(X = 5), then:

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

[tex]P(X = 5) = C_{5,5}.(0.4737)^{5}.(0.5263)^{0} = 0.0239[/tex]

0.0239 = 2.39% probability that you will win all five games.

Item c:

This probability is:

[tex]P(X \leq 2) = P(X = 0) + P(X = 1) + P(X = 2)[/tex]

Then

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

[tex]P(X = 0) = C_{5,0}.(0.4737)^{0}.(0.5263)^{5} = 0.0404[/tex]

[tex]P(X = 1) = C_{5,1}.(0.4737)^{1}.(0.5263)^{4} = 0.1817[/tex]

[tex]P(X = 2) = C_{5,2}.(0.4737)^{2}.(0.5263)^{3} = 0.3271[/tex]

[tex]P(X \leq 2) = P(X = 0) + P(X = 1) + P(X = 2) = 0.0404 + 0.1817 + 0.3271 = 0.5492[/tex]

0.5492 = 54.92% probability that you will win no more than two games.

A similar problem is given at https://brainly.com/question/24863377