Math Problem Statement

Find P(12, 5)

Solution

The notation P(12,5)P(12, 5) represents a permutation. Specifically, it is the number of ways to arrange 5 items from a set of 12 distinct items. The formula for calculating permutations is:

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

Where:

  • nn is the total number of items (12 in this case),
  • rr is the number of items to arrange (5 in this case),
  • n!n! is the factorial of nn, and
  • (nr)!(n - r)! is the factorial of nrn - r.

Step-by-step calculation:

P(12,5)=12!(125)!=12!7!P(12, 5) = \frac{12!}{(12 - 5)!} = \frac{12!}{7!}

We know that: 12!=12×11×10×9×8×7!12! = 12 \times 11 \times 10 \times 9 \times 8 \times 7! Thus, the 7!7! terms cancel out, leaving: P(12,5)=12×11×10×9×8P(12, 5) = 12 \times 11 \times 10 \times 9 \times 8

Now, multiplying these values: 12×11=13212 \times 11 = 132 132×10=1320132 \times 10 = 1320 1320×9=118801320 \times 9 = 11880 11880×8=9504011880 \times 8 = 95040

So, P(12,5)=95,040P(12, 5) = 95,040.

Final Answer:

P(12,5)=95,040P(12, 5) = 95,040


Would you like a more detailed explanation, or is there any part you'd like me to clarify?

Here are some related questions you might find interesting:

  1. How is the formula for permutations derived?
  2. What is the difference between permutations and combinations?
  3. How do you calculate combinations using the formula C(n,r)C(n, r)?
  4. How can we apply permutations in real-life problems, like arranging a set of books on a shelf?
  5. What are some examples of when order matters in probability problems?

Tip: Always remember that in permutations, the order of selection does matter!

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Math Problem Analysis

Mathematical Concepts

Permutations
Factorial

Formulas

P(n, r) = n! / (n - r)!

Theorems

Factorial properties

Suitable Grade Level

Grades 9-11