Table of Contents

## What is Combinatorics?

Combinatorics is a branch of mathematics that deals with the study of finite or countable discrete structures. In other words, it is the study of the number of possible ways that a certain number of objects can be arranged or combined.

## What is Combinatorics? Combinatorial Meaning

Combinatorics is the study of counting, shapes and structures using mathematical techniques. It is often considered a branch of discrete mathematics.

## Combinatorics Formula

The binomial theorem states that for every positive integer n, there is a unique binomial coefficient. The binomial coefficient is the coefficient of the x raised to the power of n in the expansion of

(x + y)n.

The binomial theorem can be proved using induction. The basis of the induction is that the theorem is true for n = 0. The induction step is that the theorem is also true for n = k, where k is a positive integer greater than 0.

The binomial theorem can also be derived from the fact that the binomial coefficient is the coefficient of the x raised to the power of n in the expansion of (x + y)n. To see this, note that the expansion of (x + y)n is

Each term in this expansion can be written as a product of two factors: a term in the expansion of xn and a term in the expansion of yn. The coefficient of the x raised to the power of n in the expansion of (x + y)n is the product of the coefficient of the x raised to the power of n in the expansion of xn and the coefficient of the y raised to the power of n in the expansion of yn.

## What are the Combinatorics Applications?

Combinatorics is the study of finite or countable discrete structures. It is a branch of mathematics that deals with the enumeration, combination, and permutation of objects.

## Some of the Other Combinatorics Applications are as Follows:

-Finding the number of ways to partition a set

-Finding the number of ways to choose k objects from a set

-Finding the number of ways to choose m objects from a set, when order matters

-Finding the number of ways to choose k objects from a set, when order does not matter

-Finding the number of ways to partition a set into two parts

-Finding the number of ways to partition a set into three parts

## What are Permutation and Combination?

Permutation is a mathematical term for the number of different ways that a given number of items can be arranged. For example, if you have three items, there are six permutations (3!), which is equal to 3x2x1 = 6. This is because there are three different ways to order the first item, two different ways to order the second item, and one way to order the third item.

Combination is a mathematical term for the number of different ways that a given number of items can be selected from a given set of items. For example, if you have three items and you want to select two, there are six combinations (3!/(2!x1!)), which is equal to 3×2 = 6. This is because there are three different ways to select the first item, two different ways to select the second item, and one way to select the third item.

## Combinatorics Problems – Solved Example

Problem:

In how many ways can a committee of six be chosen from a group of ten people?

There are 10! or 3,628,800 ways to choose a committee of six people from a group of ten people.