Glencoe Math: Course 2, Volume 2
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Glencoe Math: Course 2, Volume 2 View details
6. Permutations
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Exercise 1 Page 768

One student cannot be chosen for two roles.

13 800

Practice makes perfect

We want to determine in how many ways can a president, vice president, and secretary be randomly selected from a class of 25 people.

Choices for President Choices for Vice President Choices for Secretary

Since there are 25 students, we have 25 ways to choose the president.

Choices for President Choices for Vice President Choices for Secretary
25

Since the vice president cannot be the president, we have 25-1= 24 ways to choose the vice president.

Choices for President Choices for Vice President Choices for Secretary
25 24

Now, since 2 students have their roles chosen, there are 25-2= 23 ways to choose the secretary.

Choices for President Choices for Vice President Choices for Secretary
25 24 23

Next, recall that we can use the Fundamental Counting Principle to find the answer. In this case, the number of ways to choose 3 roles is the product of the number of ways to choose each of them. 25* 24* 23 Now, let's calculate this product. 25 * 24 * 23 = 13 800