SOLUTION: In a large bag of marbles, 40% of them are red. A child chooses 4 marbles from this bag. If the child chooses the marbles at random, what is the chance that the child gets exactly

Algebra ->  Probability-and-statistics -> SOLUTION: In a large bag of marbles, 40% of them are red. A child chooses 4 marbles from this bag. If the child chooses the marbles at random, what is the chance that the child gets exactly       Log On


   

Question 1099494: In a large bag of marbles, 40% of them are red. A child chooses 4 marbles from this bag. If the child chooses the marbles at random, what is the chance that the child gets exactly three red marbles?

0.1536

0.2304

0.3456

0.1920
Answer by greenestamps(13200) About Me  (Show Source):
You can put this solution on YOUR website!

I will assume that, since the problem says there is a large number of marbles in the bag, it means we can consider the probability of getting a red marble on the later choices is still 40%.

Three red marbles in four choices can happen in four different ways: RRRG, RRGR, RGRR, or GRRR.

The probability for each of those cases is %280.6%29%280.6%29%280.6%29%280.4%29+=+0.0384.
So the probability of getting 3 reds in 4 choices is 4%2A0.0384+=+0.1536