**Well this is an definitely a new way of learning, I learned quite a few things just by researching and doing this, and I hope I can learn just as easily for combinations... Sorry for any repeats. That's all.**

**A permutation is a set of objects that are arranged in a certain order, where the order is important.**

__Definition:__

**Formula:**n is the total number of objects ; r is the number of objects chosen .**Examples:**

**Number 1:**You want to know how many orders your cd player will play your 13 song cd, on shuffle mode. At first there is a one in fourteen chance that any song will be played. The next song only has 1 in 12 chance of being played, because there are only 13 songs left to be played. The possibility of outcomes of a song being played decreases by one each time. The following will be the used formula.

P(n) = 13!

__OR__

P(n) = 13*12 * 11 * 10 * 9 * 8 * 7 * 6 * 5 * 4 * 3 * 2 * 1 =6227020800 ways of playing the same CD, in different orders.

**(from Webct learning)**

__Number 2__How many five-letter "words" can be made from the alphabet if no letters are repeated? A "word" in this case is any five-letter arrangement with all letters different.

**We will use the formula to answer this question.**

__Solution:__The value of 'n' is 26 (there are 26 objects to choose from) and the value of 'r' is 5 (we pick five letters).

The formula may be convenient to use, but it is not essential. You can always find the number of arrangements (permutations) by multiplication as shown below.

**Links**Permutations Calculator

Easy Permutations

More Examples

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