Right and Wrong Permutations and Combinations Methods And Pointers That Will Make You Ace These On Your CSET Exam

You need to know permutations and combinations if you are studying for the CSET Math or the CSET Multiple Subjects exam. If you are taking the CSET Multiple Subjects exam, a brief reading over should suffice; however, if you are taking the CSET Math then you need to study this lesson very closely for the probability section of the exam.

We will study permutations, then combinations, watch a few videos, and close the lesson with a CSET practice test. You will also be given a permutations and combinations calculator that you can use to test the solution of your own problems. The most effective way to use the permutations and combinations calculator at the end of this lesson is to grab a paper and pencil and create your own permutations and combinations problems. You then use the calculator at the end of this lesson to check your answers.

Permutations

Permutations are for calculating the number of ways a task can be arranged or ordered.

When you need to count the number of ways you can arrange items where ORDER is important, then you can use permutation to count.

The factorial symbol is the exclamation point: !

When you are asked to solve 3! what this means is: (3)(2)(1) = 6

The Permutation Formula

An ORDER of arrangements of r objects, without repetition, selected from n distinct objects is called a permutation of n objects taken r at a time, and is denoted as:

Example: In how many ways can the 3 letters A, B, and C be arranged?