# COMBIN

The COMBIN function calculates the number of combinations for a given number of items. A combination is a way of selecting items from a larger set where order does not matter. This function is commonly used in probability and statistics.

## Usage

Use the COMBIN formula with the syntax shown below, it has 2 required parameters:

Parameters:
1. n (required):
The total number of items to choose from.
2. k (required):
The number of items to choose from the total.

## Examples

Here are a few example use cases that explain how to use the COMBIN formula in Google Sheets.

### Choosing a Committee

If a group of 10 people are running for a committee and 5 need to be chosen, COMBIN(10,5) would give the number of possible combinations of committee members.

### Poker Hands

In poker, a hand is a combination of 5 cards. COMBIN(52,5) would give the number of possible unique poker hands.

If a password is 8 characters long and can contain uppercase letters, lowercase letters, and numbers, COMBIN(62,8) would give the number of possible password combinations.

## Common Mistakes

COMBIN not working? Here are some common mistakes people make when using the COMBIN Google Sheets Formula:

### Incorrect order of arguments

Make sure to enter the n value first and the k value second, otherwise the formula will not work correctly.

### Using non-numeric values

COMBIN only works with numeric values, so make sure to enter numbers for n and k. If you enter text or other non-numeric values, the formula will return an error.

### Entering a negative value for n or k

COMBIN only works with positive values for n and k. If you enter a negative value for either of these arguments, the formula will return an error.

### Using decimal values for n or k

COMBIN only works with whole numbers for n and k. If you enter a decimal value for either of these arguments, the formula will round down to the nearest whole number.

### Incorrectly calculating combinations

Make sure you understand the formula for calculating combinations before using COMBIN. The formula is n! / (k! * (n - k)!), where n is the total number of items, and k is the number of items you want to choose. If you enter the wrong values for n and k, you will get the wrong result.

The following functions are similar to COMBIN or are often used with it in a formula:

• PERMUT

The PERMUT function returns the number of permutations of a set of objects. A permutation is a way of arranging objects in a specific order. The function takes two arguments: n, the total number of objects, and k, the number of objects to arrange. The result is the number of possible permutations. This function is commonly used in combinatorics and probability theory.

• BINOMDIST

The BINOMDIST function calculates the probability of a certain number of successes in a fixed number of trials given a constant probability of success for each trial. This function is commonly used in statistical analysis and hypothesis testing.

• RAND

The RAND function returns a random number between 0 and 1. This function is often used in combination with other functions to generate random values for simulations, games, or statistical analysis.

• SUM

The SUM function in Google Sheets adds up a range of numbers. This function is most commonly used to sum the values in a range of cells.

• COUNT

The COUNT formula returns the number of numeric values within a specified range of cells. It is commonly used to count the number of entries in a given range that meet specific criteria, such as counting the number of sales above a certain threshold.