Chapter 5: Problem 13
Find the value of each permutation. $$ { }_{4} P_{4} $$
Short Answer
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Step by step solution
01
Understand the Permutation Notation
The notation \({ }_{n} P_{r}\) represents the number of permutations of n items taken r at a time. The formula is given by \({ }_{n} P_{r} = \frac{n!}{(n-r)!}\).
02
Identify the Values of n and r
In the given problem, \({ }_{4} P_{4}\), n = 4 and r = 4.
03
Apply the Permutation Formula
Substitute the values of n and r into the formula: \({ }_{4} P_{4} = \frac{4!}{(4-4)!}\).
04
Evaluate the Factorials
Compute \(4! \) and \(0! \): \(4! = 4 \times 3 \times 2 \times 1 = 24\) and \(0! = 1\).
05
Calculate the Permutation Value
Use the factorial values in the formula: \({ }_{4} P_{4} = \frac{4!}{0!} = \frac{24}{1} = 24\).
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Key Concepts
These are the key concepts you need to understand to accurately answer the question.
Permutation Formula
Permutations are a key part of combinatorial mathematics, representing the different ways to arrange or order a set of items. The permutation formula \( { }_{n} P_{r} = \frac{n!}{(n-r)!} \) helps calculate the number of distinct arrangements of n items taken r at a time. This formula is highly valuable in solving problems where the order of selection matters.Let's break the formula down:
- n is the total number of items.
- r is the number of items being chosen and arranged.
- n! (n factorial) is the product of all positive integers up to n.
- (n-r)! ((n-r) factorial) is the product of all positive integers up to (n-r).
Factorials
Factorials are fundamental to understanding permutations. A factorial, denoted by an exclamation mark (e.g., 4!), is the product of all positive integers up to a given number. For example, \( 4! = 4 \times 3 \times 2 \times 1 = 24 \).Here are a few key properties of factorials:
- 0! is defined as 1.
- Factorials grow very quickly; 5! = 120, 6! = 720, and so on.
Combinatorial Mathematics
Combinatorial mathematics is a branch of mathematics dealing with combinations, permutations, and the counting of objects. It is essential in fields like computer science, statistics, and game theory.In combinatorial mathematics:
- Permutations involve arranging objects in specific order (order matters).
- Combinations involve selecting objects without regard to order (order doesn't matter).
- Arranging books on a shelf.
- Scheduling tasks or events.
- Forming codes or passwords.