Combination with Repetition Calculator
Verified Calculation Engine
The online Combination with Repetition Calculator helps you calculate instantly and solve problems related to Permutations Combinations. This tool provides accurate results using standard formulas and step-by-step calculation; you can view the formula with example in the calculator where available. Whether you are a student, teacher, or professional, this calculator simplifies complex calculations and saves time. Enter the required values below and get instant results. Results are shown clearly, with optional step-by-step explanation where applicable. The tool is free to use and works in any modern browser—no download or installation required. Bookmark this page for quick access whenever you need reliable Math Numbers calculations.
Calculates combinations with repetition allowed: (n+r-1)Cr = number of ways to choose r objects from n types with repetition.
Combinations with repetition = (n+r-1)Cr = (n+r-1)! / [r!(n-1)!]
Also called 'stars and bars' method
When repetition is allowed, use formula (n+r-1)Cr
Inputs
Results
Worked Examples
Example 1: Basic
How many ways to choose 3 fruits from 4 types (apple, banana, orange, mango) with repetition?
- n: 4
- r: 3
- combination: 20
- formula: (4+3-1)C3 = 6C3 = 20
Example 2: Board Level
How many ways to choose 5 items from 3 types with repetition?
- n: 3
- r: 3
- combination: 21
- formula: (3+5-1)C5 = 7C5 = 21
How to Use This Calculator
- Enter the required values in the input fields.
- Click the Calculate button.
- View the computed result instantly.
Formula Used
Combinations with repetition = (n+r-1)Cr = (n+r-1)! / [r!(n-1)!]
Also called 'stars and bars' method
When repetition is allowed, use formula (n+r-1)Cr
Example Calculation
Example: If we input the following values:
- n: 4
- r: 3
For example, substituting these values into the formula gives the computed result as shown above. This demonstrates how the calculation works step-by-step.
Frequently Asked Questions
What is Combination with Repetition Calculator?
- Combination with Repetition Calculator is an online calculator that helps you compute results for problems in this category quickly and accurately. It uses established formulas and shows the result instantly. You can use it for homework, projects, or everyday calculations. Try it with a sample input to see the formula and example output in action.
How does Combination with Repetition Calculator work?
- Enter the required values in the input fields and click Calculate. The calculator applies the relevant formula and displays the result. Step-by-step explanation may be available depending on the calculator. If you prefer manual calculation, you can use the same formula shown in the tool.
Why use this Math Numbers calculator?
- This Math Numbers calculator is free, works in your browser, and gives accurate results without installation. It is useful for students, teachers, and professionals who need quick and reliable calculations. The underlying formula is based on standard principles, so you can verify results by hand if needed.