conditional probability

posted by .

You have two bags of marbles.

Bag 1 has 5 red and 6 blue marbles.
Bag 2 has 20 green and 5 red marbles.

What is the probability of drawing a red marble out of Bag 2, given that you drew a red marble out of Bag 1?

  • conditional probability -

    5/25 = 1/5

    It makes no difference what color she drew from Bag 1.

  • conditional probability -

    P(R1)=5/11
    P(R2)=5/25

    Since the drawing of the two bags are independent, we have
    P(R1∩R2)=P(R1)*P(R2)

    P(R2|R1)=P(R2∩R1)/P(R1)
    =P(R1)*P(R2)/P(R1)
    =P(R2)
    =1/5 as Ms.Sue had it.

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. math

    A bag contains red, blue, and orange marbles. If the probability of randomly selecting a red marble is 0.4 and the probability of selecting a red or blue marble is 0.9 what is the probability of selecting a red or orange marble?
  2. Math Probability

    In a bag of 10 marbles, there are 5 blue marbles, 3 red marbles, and 2 white marbles. Complete the probability distribution table for drawing 1 marble out of the bag Probability Blue marble Red marble White marble Total:
  3. Math

    A bag of marbles contains only green and red marbles. All of the marbles are the same size. If the probability of selecting a green marble is 1/2. Which is most likely to be the number of green and red marbles in the bag?
  4. Math :)

    In a bag of 10 marbles, there are 5 blue marbles, 3 red marbles, and 2 white marbles. Complete the probability distribution table for drawing 1 marble out of the bag. Draw a: Probability Blue marble 5/10 Red marble 3/10 White marble …
  5. Math

    A bag contains nine red marbles, four green marbles, three blue marbles, and two yellow marbles. If Lisa draws a random marble from the bag, what is the probability that it will be a red, green, or blue marble?
  6. math

    A bag contains 5 red marbles, 6 white marbles, and 8 blue marbles. You draw 5 marbles out at random, without replacement. What is the probability that all the marbles are red?
  7. Math

    A bag contains 9 red marbles, 8 white marbles, and 6 blue marbles. You draw 4 marbles out at random, without replacement. What is the probability that all the marbles are red?
  8. Algebra

    A bag of marbles contains 3 yellow marble, 3 red marbles, and 5 green marbles. If a marble is chosen, put back in the bag and then a second marble is chosen, what is the probability that both marbles will be red?
  9. statistics

    a bag contains 4 blue marbles,6 red marbles, 10 yellow marbles and 6 green marbles.What is the probability of not drawing a red marble?
  10. Math-Algebra 1

    You have a bag which contains only red and green marbles. In this bag with x^2+5 marbles total, x+1 are red. Also, x-3 marbles have a scratch on them. The probability of drawing a red marble from the original bag is equal to that of …

More Similar Questions