A bag contains 3 gold marbles, 6 silver marbles, and 30 black marbles. The rules of the game are as follows: You randomly select one marble from the bag. If it is gold, you win $6, if it is silver, you win $5. If it costs $1 to play, what is your expected profit or loss if you play this game?

Respuesta :

Answer:

The expected profit is $0.23077.

Step-by-step explanation:

From the given information it is clear that

Gold marbles = 3

Silver marbles = 6

Black marbles = 30

Total number of marbles = 3+6+30=39

The probability of selecting gold marble is

[tex]\frac{3}{39}=\frac{1}{13}[/tex]

The probability of selecting silver marble is

[tex]\frac{6}{39}=\frac{2}{13}[/tex]

The probability of selecting black marble is

[tex]\frac{30}{39}=\frac{10}{13}[/tex]

It is given that If it is gold, you win $6, if it is silver, you win $5. If it costs $1 to play. Then the expected profit is

Expected profit or loss = 6(Probability of gold marble)+5(Probability of silver marble)-1

Expected profit or loss = [tex]6(\frac{1}{13})+5(\frac{2}{13})-1[/tex]

Expected profit or loss = [tex]\frac{6}{13}+\frac{10}{13}-1[/tex]

Expected profit or loss = [tex]\frac{6+10-13}{13}[/tex]

Expected profit or loss = [tex]\frac{3}{13}[/tex]

Expected profit or loss = 0.23076923

Expected profit or loss ≈ 0.23077

Positive sigh represents the profit.

Therefore the expected profit is $0.23077.