Math Problem Statement

A class has 33 students. In how many different ways can five students form a group for an​ activity? (Assume the order of the students is not​ important.) Question content area bottom Part 1 There are    enter your response here different ways that the five students can form a group for an activity. ​(Type a whole​ number.)

Solution

Since the order of students is not important, this is a combinatorics problem. We are asked to find how many ways five students can be selected from a group of 33 students.

The formula for combinations is:

(nr)=n!r!(nr)!\binom{n}{r} = \frac{n!}{r!(n-r)!}

Where:

  • nn is the total number of students (33),
  • rr is the number of students to choose (5),
  • "!" denotes factorial.

Now we can calculate:

(335)=33!5!(335)!=33!5!28!\binom{33}{5} = \frac{33!}{5!(33-5)!} = \frac{33!}{5!28!}

I'll compute this.There are 237,336 different ways for five students to form a group for the activity.

Would you like further explanation or details?

Here are 5 related questions to consider:

  1. How many ways can you select 3 students from the 33 students?
  2. What if the order of selection mattered? How many different groups could you form then?
  3. How many ways can you form a group of 5 students from a class of 40 students?
  4. What if 2 specific students must be included in the group? How many ways can you select the remaining students?
  5. How many ways can you form two groups of 5 from the class of 33 students?

Tip: When order doesn't matter, use combinations; when it does, use permutations!

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Math Problem Analysis

Mathematical Concepts

Combinatorics
Combinations

Formulas

Combination formula: C(n, r) = n! / (r!(n-r)!)

Theorems

Fundamental Principle of Counting

Suitable Grade Level

Grades 9-12