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Homework Help: Marble bag

  1. Oct 25, 2005 #1
    There are 10 marbles in a bag, 9 white and 1 black. Each day a teacher goes around the room of 10 students and allows each student to pick one marble. The one who draws the black marble gets candy for the day. The students never change their seats and she always distribute the marbles along the same path (the first person is always the first person to draw and the last person is always the last to draw). Does each student have an equal chance to win candy for the day? How would the probability be calculated for third person in line?
    I thought every student has an equal chance of 10% an the probability for the third person would be 1/8*9/10*8/9 (the prob. that 3rd person draws it times the prob. that the first person did not draw it times the prob. that the 2nd person didnt draw it) But i dont know if i am making a wrong asumption that the third person even has a chance. please help
  2. jcsd
  3. Oct 25, 2005 #2
    Your analysis sounds fine to me.
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