PERMUTATION AND COMBINATION

OBJECTIVES 

1. Define Permutation and Combination 

2. Learn how work on Permutation and Combination 

What is permutation? 

Permutation is a calculation of the number of different ways that a certain number of objects can be arranged in order from a huge number of objects. 

Working for Permutation: 

What is Combination? 

Combination is a collection of the number of different ways that a certain number of objects as a group be selected from a large number of objects.

Working for Combination:

Always REMEMBER : 

n = permutation 

r = Number Selected 

! = Factorial 

Lets take a look on some examples

Example 1

 How many ways you can arrange 8 objects

Permutation 

Combination 

Lets take another example...

Example 2 : 

Example 2 Permutation

let's say we just want to know which 3 pool balls are chosen, not the order.

We already know that 3 out of 16 gave us 3,360 permutations.

But many of those are the same to us now, because we don't care what order!

Example 2 Combinations

Example 3 :

How many permutations of 3 different digits are there, chosen from the ten digits 0 - 9 inclusive

Such as drawing ten numbered marbles from a bag, without replacement

Lets take an exercise...

exercise 1 

How many permutations of 4 different letters are there, chosen from the twenty six letters of the alphabet?