SOLUTION: A bag contains 5 red marbles, 10 blue marbles, and 20 green marbles.
If two marbles are taken out at random, one by one, without replacement, what is the probability that they ar
Algebra.Com
Question 727138: A bag contains 5 red marbles, 10 blue marbles, and 20 green marbles.
If two marbles are taken out at random, one by one, without replacement, what is the probability that they are both blue?
I know the total is 35 marbles but I am unsure how to calculate. I attempted to do 10/35, 9/34 and so forth and added all the results together but I fear it is not correct.
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
A bag contains 5 red marbles, 10 blue marbles, and 20 green marbles.
If two marbles are taken out at random, one by one, without replacement, what is the probability that they are both blue?
I know the total is 35 marbles but I am unsure how to calculate. I attempted to do 10/35, 9/34 and so forth and added all the results together but I fear it is not correct.
----
# of ways to pick 2 blue: 10C2 = 45
# of ways to pick a random pair: 35C2 = 595
----
P(2 blue without replacement) = 45/595 = 9/119
------------------
Cheers,
Stan H.
==================
RELATED QUESTIONS
A bag contains 5 blue marbles, 6 red marbles, and 9 green marbles. Two marbles are drawn... (answered by stanbon)
One bag contains 3 red marbles & 4 green marbles. Another bag contains 2 green marbles &... (answered by stanbon)
4. A bag of 10 marbles contains 3 red marbles and 7 blue marbles. If two marbles are... (answered by stanbon)
A bag contains 4 blue marbles, 6 green marbles, and 2 red marbles. You select one ball at (answered by rfer)
A bag contains 5 red marbles, 10 white marbles, and 6 blue marbles. You draw 5 marbles... (answered by scott8148)
A bag contains 5 red marbles, 10 white marbles, and 8 blue marbles. You draw 5 marbles... (answered by ewatrrr)
A bag contains 5 red marbles, 10 white marbles, and 8 blue marbles. You draw 5 marbles... (answered by ewatrrr)
A bag contains 10 red marbles, 9 white marbles, and 8 blue marbles. You draw 5 marbles... (answered by greenestamps)
A bag contains 6 marbles Three red marbles two blue marbles and one white marble If two... (answered by stanbon)