Question

A bag contains 10 red marbles, 7 white marbles, and 9 blue marbles. You draw 5 marbles out at random, without replacement. For the questions below, enter your answers in fraction form. 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

ALL RED = 19/5000

Two Red = 3831/10000

No red marbles = 16/26

Explanation:

1. Find the total number of marbles

7+10+9= 26

2. There are 10 red marbles so the probability that the first marble is red 10/26

3. When the second marble there are 25 marbles so the probability that it is red is 9/25

4. Third Marble probability

8/24

5. Fourth Marble probablity

7/23

6. Fifth marble probability

6/22

7. Now to find that ALL the marbles are red you multiply all the fractions above

10/26 * 9/25 * 8/24 * 7/23 * 6/22 = 0.0038

8. Convert to fraction form

19/5000

9. Two marbles are red

5!/(3!*2!) * 10/26 * 9/25 * 16/24 * 15/23 * 14/22 = 0.3831

10. Convert to fraction

3831/10000