# Combination and permutation

A combination is a selection of items from a set where the order is not important. For example, if you have a set of three items, say a, b, and c, then the following are all combinations of two items:

ab, ac, bc

A permutation is a selection of items from a set where the order is important. For example, if you have a set of three items, say a, b, and c, then the following are all permutations of two items:

ab, ba, ac, ca, bc, cb

As you can see, a permutation includes all of the combinations, plus additional selections where the order is important. What is the example of combination? A combination is an unordered selection of items from a set. For example, if you have a set of three items, say A, B, and C, then there are three possible combinations: A, B, and C; A and B; or A and C.

##### What is the rule of permutation and combination?

There are two types of permutations and combinations:

1. Permutations
2. Combinations

1. Permutations

A permutation is an arrangement of objects in a specific order. For example, if you have a deck of cards, you can arrange them in many different ways. This is known as a permutation.

There are two types of permutations:

a. Permutations with repetition
b. Permutations without repetition

a. Permutations with repetition

Permutations with repetition are those in which you are allowed to repeat objects. For example, if you have a deck of cards, you can arrange them in many different ways. This is known as a permutation with repetition.

b. Permutations without repetition

Permutations without repetition are those in which you are not allowed to repeat objects. For example, if you have a deck of cards, you can arrange them in many different ways. This is known as a permutation without repetition.

2. Combinations

A combination is a selection of items from a set, without regard to the order in which they are selected. For example, if you have a deck of cards, you can choose any combination of cards. This is known as a combination.

There are two types of combinations:

a. Combinations with repetition
b. Combinations without repetition

a. What is an example of a permutation? A permutation is an arrangement, or listing, of objects in which the order is important. For example, the permutation (2,3,1) is different from (3,1,2) and from (1,2,3).

### What is permutation and combination with an example?

Permutation is an arrangement of objects in a definite order. Combination is a selection of objects without a definite order.

An example of a permutation would be the five different ways you can arrange the letters in the word "cat":

cat
act
tca
atc
tac

An example of a combination would be the three different ways you can select two letters from the word "cat":

ca
at
ct What is called combination? A combination is a selection of items from a set, where the order is not important. For example, if you have a set of three items, say a, b, and c, then there are three possible combinations: a + b, a + c, and b + c.