Math
posted by Chris
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?
What is the probability that exactly two of the marbles are red?
The probability that exactly two of the marbles are red is...?

something
9/23 bc there are 9 red marbles and 23 marbles altogether

potato
^thats only for choosing one marble out of the bag
you have to solve for choosing 4 marbles out of the bag, and 2 of them are red 
Reiny
prob(4reds)
= (9/23)(8/22)(7/21)(6/20)
= 18/1265
or
prob(4reds)
= C(9,4) / C(23,4) = 126/8855 = 18/1265
= appr .014
prob(2 out of 4 are red)
= C(9,2) * C(14,2)/C(23,4)
= 36*91/8855
= 468/1265 = appr .37
Respond to this Question
Similar Questions

mathalgebra
7. A bag contains 5 red marbles, 6 green marbles, and 9 blue marbles. Suppose 3 marbles are chosen without replacement. What is the probability of choosing a red, a blue, and a red in that order? 
mathalgebra
7. A bag contains 5 red marbles, 6 green marbles, and 9 blue marbles. Suppose 3 marbles are chosen without replacement. What is the probability of choosing a red, a blue, and a red in that order? 
Math
A box contains four red marbles, seven white marbles, and five blue marbles. If two marbles are drawn one at a time, find the probability that both marbles are white if the draws are made as follows: (a) With replacement ____________ … 
probability
George has a bag of marbles. Inside the bag are 5 red marbles, 3 red marbles, and 2 blue marbles. He draws out two marbles in a row, without replacement. What is the number of outcomes? 
math
A bag of marbles contains 8 red marbles and 6 yellow marbles. Two marbles are drawn out of the bag at random without replacement. What is the probability that two red marbles are drawn out? 
Math
A bag contains 3 red marbles, 4 blue marbles, and 5 white marbles. What is the probability of pulling out two red marbles in a row if none are replaced? 
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? 
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? 
Math "Need Help Asap"!
1.)There are 35 marbles in a bag:9 blue marbles, 8 marbles, 4 red marbles, 4 red marbles, 8 white marbles, & 6 yellow marbles. Find P(Red). Write the probability as a fraction in simplest form, a decimal, & a percent. A.)4/31, 0.129, … 
Math
A bag contains 4 blue marbles and 4 red marbles. If three marbles are drawn in a row without replacement, find the probability that the marbles will be the same colour?