Question

A bag contains 7 red marbles, 9 white marbles, and 9 blue marbles. You draw 4 marbles out at random, without replacement. What is the probability that all the marbles are red?

The probability that all the marbles are red is .

What is the probability that exactly two of the marbles are red?

The probability that exactly two of the marbles are red is .

What is the probability that none of the marbles are red?

The probability of picking no red marbles is .

Answer 1

For finding the probability of getting exactly two marbles we use that two red marbles are drawn (out of 7) and remaining two are drawn from 18 marbles (9whitw and 9 blue).

For finding the probability of no red marble is drawn we use that all the four are drawn from 18 marbles (9 white and 9 blue).

The detailed solution is attached below.