Permutation and Combination

PERMUTATION
The number of different ways that a certain number of objects can be arranged in order from a huge number of objects. 

• If the order DOES matter, it is a Permutation

COMBINATION
The number of different ways that a certain number of objects as a group be selected from a large number of objects.

• If the order DOES NOT matter, it is a Combination.

Note: n = Permutation 
          r = Number selected
          ! = Factorial 
 
Example 1:
How many ways you can arrange 8 objects?

Permutation:

Combination:

Example 2:
The runner of 4 women and 3 men is to be chosen from the field of 9 people from a group of 8 men and 6 women. How many possible combination of runner can be selected?

Example 3:
How many permutations for the letter of Blogger?

= Count how many letter in the horizontal and count each of the letter. 

BLOGGER = 7 letter.

 B - 1
 L -  1
 O - 1
 G - 2
 E - 1
 R - 1