# An urn contains seven red balls, seven white balls, and seven blue balls and a sample of five balls is drawn at random without replacement.  a. Compute the probability  that the sample contains four balls of one color and one of another color   b.  compute the probability that all of the balls in the sample space are the same color  c. Compute the probability that the sample contains at least one ball of each color

Question
3803 views

An urn contains seven red balls, seven white balls, and seven blue balls and a sample of five balls is drawn at random without replacement.

a. Compute the probability  that the sample contains four balls of one color and one of another color

b.  compute the probability that all of the balls in the sample space are the same color

c. Compute the probability that the sample contains at least one ball of each color

check_circle

Step 1

Given total red balls = 7

Total white balls = 7

Total blue balls = 7

A sample of five balls is drawn at random without replacement.

we need probability that we get four balls of one colour and one ball of another colour.

Total number of balls in urn = 7+7+7 = 21

The total number of ways of picking five balls from 21 balls = 21C5

First we need to pick one colour from three three colours = 3C1

Number of ways of selecting four balls of one colour = 7C4

Number of ways of selecting one colour from remaining two colours = 2C1

Number of ways of selecting one ball from that colour = 7C1

So number of ways of selecting five balls with four of one colour and one of different colour is calculated as shown below. Its probability = 0.0722

Step 2

The total number of ways of selecting five balls from 21 balls = 21C5

The number of ways of selecting one colour = 3C1

The total number of ways of selecting five balls from 7 balls = 7C5

The total number of choosing five balls of one colour = &n...

### Want to see the full answer?

See Solution

#### Want to see this answer and more?

Solutions are written by subject experts who are available 24/7. Questions are typically answered within 1 hour.*

See Solution
*Response times may vary by subject and question.
Tagged in

### Basic Probability 