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...?
3 answers
9/23 bc there are 9 red marbles and 23 marbles altogether
^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
you have to solve for choosing 4 marbles out of the bag, and 2 of them are red
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
= (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
1 answer