SOLUTION: A bag contains 2 gold marbles, 10 silver marbles, and 30 black marbles. Someone offers to play this game: You randomly select one marble from the bag. If it is gold, you win $3. If

Algebra ->  Probability-and-statistics -> SOLUTION: A bag contains 2 gold marbles, 10 silver marbles, and 30 black marbles. Someone offers to play this game: You randomly select one marble from the bag. If it is gold, you win $3. If      Log On


   

Question 1148222: A bag contains 2 gold marbles, 10 silver marbles, and 30 black marbles. Someone offers to play this game: You randomly select one marble from the bag. If it is gold, you win $3. If it is silver, you win $2. If it is black, you lose $1.
What is your expected value if you play this game?
Answer by ikleyn(52814) About Me  (Show Source):
You can put this solution on YOUR website!
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Note that the total number of marbles in the box is  2+10+30 = 42 originally.


The Math expectation of the win value is


    3%2A%282%2F42%29+%2B+2%2A%2810%2F42%29+-+1%2A%2830%2F42%29 = %283%2A2+%2B+2%2A10+-30%29%2F42 = -4%2F42 = -2%2F21  of a dollar.     ANSWER