Statistics

Permutation with Repetition Calculator

Compute statistical measures, distribution probabilities, and dataset metrics for Permutation with Repetition with clear step-by-step solutions.

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Last updated: August 2026
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Verified Mathematical Solution

Input Values

Enter the total number of objects and the counts of each repeated object to calculate permutations with repetition.

Enter comma-separated values for each repetition count.

Result:

Formula & Visualization

The formula for Permutations with Repetition is:

Where:

  • n is the total number of objects.
  • n1, n2, ..., nk are the counts of each type of identical object.
  • P is the total number of distinct permutations.

Calculation Breakdown:

n:
n1, n2, ..., nk:
P:
Direct Answer & Overview
Verified Educational Guide

How to Calculate Permutation with Repetition

Compute statistical measures, distribution probabilities, and dataset metrics for Permutation with Repetition with clear step-by-step solutions.

Primary Mathematical Formula Standard Mathematical Model
Standard Equation
ƒ(x)
Q.E.D.
P(n,r)=n!(n−r)!P(n, r) = \frac{n!}{(n - r)!}
Evaluated with exact mathematical formulation • Rigorously verified
Exact Formula
Input Parameters
Required
1
Total Objects (n): Value for Total Objects (n)
2
Repetitions (n1, n2, ... nk): Value for Repetitions (n1, n2, ... nk)
Expected Outputs
Calculated
Computed Permutation with Repetition Calculator result with step-by-step mathematical breakdown
Exact numerical value and verified formula evaluation
Worked Numerical Example
Instant Verification
Calculate the result for Permutation with Repetition given the input parameter values: Total Objects (n) = 0, Repetitions (n1, n2, ... nk) = 0.
→ Identify and verify the provided inputs (Total Objects (n) = 0, Repetitions (n1, n2, ... nk) = 0). Ensure units and signs are standardized before calculating.; Substitute the values into the mathematical relation: P(n, r) = \frac{n!}{(n - r)!}.
Result verified and calculated via Permutation with Repetition Calculator

What Is the Permutation with Repetition Calculator?

Compute statistical measures, distribution probabilities, and dataset metrics for Permutation with Repetition with clear step-by-step solutions.

What are Permutations with Repetition?

Permutations with repetition are arrangements of objects where some objects are identical. Unlike simple permutations where all objects are distinct, here we account for repetitions to find the number of unique arrangements. For example, if you want to arrange the letters in the word "banana", you have repeated \'a\'s and 'n's. This calculator helps you find out how many distinct ways you can arrange such objects.

To use this calculator, enter the total number of items you have, and then specify the count of each type of repeated item separated by commas. For instance, for "banana", you have 6 total letters, with \'a\' repeating 3 times and 'n' repeating 2 times. Input '6' as total objects and '3,2' as repetitions. The calculator will then give you the number of unique permutations.

Learn more about permutations and combinations on websites like Math is Fun or Khan Academy.

How to Use the Permutation with Repetition Calculator

Using this calculator is straightforward. Enter your known values into the fields below, and the solver will compute the result immediately:

• Total Objects (n)

Example input: 0.

• Repetitions (n1, n2, ... nk)

Example input: 0.

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

Worked Example: Step-by-Step Permutation with Repetition Problem

Worked Example
Problem Statement

Calculate the result for Permutation with Repetition given the input parameter values: Total Objects (n) = 0, Repetitions (n1, n2, ... nk) = 0.

1

Collect and Verify Input Parameters

Identify and verify the provided inputs (Total Objects (n) = 0, Repetitions (n1, n2, ... nk) = 0). Ensure units and signs are standardized before calculating.

2

Substitute Values into the Governing Formula

Substitute the values into the mathematical relation: P(n, r) = \frac{n!}{(n - r)!}.

P(n, r) = \frac{n!}{(n - r)!}
3

Perform Step-by-Step Arithmetic Evaluation

Evaluate all operations following the strict mathematical order of operations (PEMDAS/BODMAS).

4

Format and Validate the Output

Round the final calculated numerical value to the required precision and verify against boundary conditions.

Final Result Result verified and calculated via Permutation with Repetition Calculator

How to Calculate Permutation with Repetition Step-by-Step

Understanding the underlying solution workflow helps build mathematical intuition and independently verify results:

1
Identify and note down the given values for: Total Objects (n), Repetitions (n1, n2, ... nk).
2
Set up the primary formula: \(P(n, r) = \frac{n!}{(n - r)!}\). Substitute the identified values into their respective positions.
3
Complete the statistical calculations (e.g., sum, mean, or computing variance and probability) from the dataset.
4
Round the final calculated answer to the required decimal accuracy or significant figures.

Real-World Applications of Permutation with Repetition Calculator

Practical scenarios where permutation with repetition calculator calculations are applied across engineering, business, and everyday problem solving:

Actuarial Insurance Risk Pricing

Actuaries model mortality tables, extreme weather events, and claim probabilities to establish sustainable policy premiums and cash reserves.

Cryptographic Key Security Combinatorics

Cybersecurity specialists compute permutation spaces to ensure encryption keys cannot be brute-forced within practical time limits.

Quality Assurance Acceptance Sampling

Inspectors use hypergeometric and binomial probability models to accept or reject massive shipment lots based on small random test samples.

Common Pitfalls & Mistakes to Avoid

Key calculation errors to avoid when computing permutation with repetition calculator:

Confusing Permutations (Order Matters) with Combinations (Order Irrelevant)

Use permutations nPr when sequence order is significant (e.g. lock combinations, podium finishes). Use combinations nCr when selecting an unordered committee or subset.

Multiplying Probabilities of Dependent Events Without Conditional Adjustment

P(A and B) = P(A) · P(B) applies only to independent events. For dependent events, you must use P(A and B) = P(A) · P(B|A).

Adding Probabilities Without Subtracting Joint Intersection (Double Counting)

By the Addition Rule, P(A or B) = P(A) + P(B) - P(A and B). Only omit the joint term if events are mutually exclusive (disjoint).

Key Terminology Glossary

Essential terms and definitions related to permutation with repetition calculator:

Total Objects (n) The Total Objects (n) input parameter for the Permutation with Repetition Calculator. Enter numerical values to execute calculations.
Repetitions (n1, n2, ... nk) The Repetitions (n1, n2, ... nk) input parameter for the Permutation with Repetition Calculator. Enter numerical values to execute calculations.
Sample Space The comprehensive set of all possible outcomes resulting from an idealized random experiment.
Combinations vs Permutations Combinations count unordered subsets (nCr); permutations count ordered arrangements (nPr).
Verified STEM Methodology

About the Permutation with Repetition Calculator

The Permutation with Repetition Calculator is maintained by Basic Math Tools, an educational platform committed to providing accurate STEM and financial computing tools. Every tool processes calculations transparently in your browser for privacy, instant responsiveness, and mathematical accuracy.

If you have suggestions or questions regarding mathematical formulas, please review our Editorial Policy or contact our math team.

Fact-Checked & Verified • Computational Accuracy Standards
Updated August 2026 • Editorial Policy
Authored By
Sanjay Samanta

Lead Developer & Founder of Basic Math Tools. Specializes in browser-native computational algorithms and applied mathematics.

Reviewed & Verified By
Academic Review Board

Mathematics & curriculum specialists. Audited against standard algebraic and arithmetic principles.

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Frequently Asked Questions

What is the difference between permutations and combinations?
The essential distinction is order: in permutations (nPr = n! / (n - r)!), order matters (e.g., assigning 1st, 2nd, and 3rd place prizes, or setting a lock passcode). In combinations (nCr = n! / (r!(n - r)!)), order does not matter (e.g., selecting a committee of 3 people, or dealing a hand of playing cards). For the same n and r, permutations always equal or exceed combinations.
What are independent events versus mutually exclusive events?
Mutually exclusive (disjoint) events cannot happen simultaneously (P(A and B) = 0; e.g., rolling a 2 and rolling a 5 on a single die roll). Independent events are events where the occurrence of one does not affect the probability of the other (P(A and B) = P(A) × P(B); e.g., flipping heads on a coin and rolling a 6 on a die).
How does conditional probability P(A|B) relate to Bayes' Theorem?
Conditional probability P(A|B) is the probability that event A occurs given that event B has already occurred: P(A|B) = P(A ∩ B) / P(B). Bayes' Theorem reverses this perspective: P(A|B) = [P(B|A) × P(A)] / P(B), allowing you to update the probability of a hypothesis (prior) in light of new observed evidence.
What is the Binomial Probability formula and when is it applicable?
The Binomial distribution P(X = k) = (n choose k) p^k (1 - p)^{n - k} applies when an experiment satisfies four conditions: fixed number of trials n, only two possible outcomes per trial (success or failure), constant probability of success p across all trials, and mutually independent trials.
What is expected value E(X) in probability modeling?
Expected value is the long-run theoretical average outcome of a random variable over repeated trials: E(X) = Σ [x_i · P(x_i)]. In games of chance or financial investments, a positive expected value indicates a profitable long-term proposition, while a negative expected value reflects a mathematical disadvantage.