*There are two questions you have to answer before solving a permutation/combination problem. In other words, can we name an object more than once in our permutation or combination? 3.) How many 3-digit numbers can be formed from the digits 3, 7, 0, 2, and 9?1.) Are we dealing with permutations or combinations? Once we have answered these questions, we use the appropriate formula to solve the problem. Let's look at some examples to get comfortable solving these types of problems. Solution: Let's consider the 3-digit number 702 formed using 3 of the 5 digits.*

Translation: n refers to the number of objects from which the permutation is formed; and r refers to the number of objects used to form the permutation. The permutations were formed from 3 letters (A, B, and C), so n = 3; and each permutation consisted of 2 letters, so r = 2.

For an example that counts permutations, see Sample Problem 1.

If I tell you they crossed the line in the order A, B, C, D, E, this would be different than if I told you they crossed the line in the order C, B, A, E, D.

Thus, the order makes a difference, so the order in which the 5 runners finish is a permutation of the 5 runners. = (20*19*18) / (3*2*1) = 1,140 Therefore, there are 1,140 ways to choose 3 people from a group of 20.

The distinction between a combination and a permutation has to do with the sequence or order in which objects appear.

A permutation, in contrast, focuses on the arrangement of objects with regard to the order in which they are arranged. Using those letters, we can create two 2-letter permutations - AB and BA.

If I said you grabbed those same 5 coins, but I said you grabbed 2 quarters, a nickel, a penny, and a dime, it is still the same group of coins.

That is, the order I name them in is insignificant.

Instructions: To find the answer to a frequently-asked question, simply click on the question.

If none of the questions addresses your need, refer to Stat Trek's tutorial on the rules of counting or visit the Statistics Glossary. A permutation is an arrangement of all or part of a set of objects, with regard to the order of the arrangement.

## Comments Solving Combination Problems

## How to Calculate the Probability of Combinations - Video & Lesson.

To calculate the probability of a combination, you will need to consider the number. Let's look at another example of how we would write and solve the factorial of 9. In this problem, John is choosing three movies from the ten new releases.…

## Combinations - West Texas A&M University

After completing this tutorial, you should be able to Use combinations to solve a counting problem involving groups.…

## Students' Errors in Solving the Permutation and Combination.

Abstract. This article was written based on the results of a study evaluating students' errors in problem solving of permutation and combination.…

## Are there any tricks to solve permutation and combination problems.

What a fun question. Years ago, I got to work as a paper-grader for a very famous statistician teaching a basic course. This gentleman had a.…

## Combinations Examples - Concepts & Word Problems

A selector should work out the different combinations to study the pros and cons of. Solution This is also a combination problem but attached some conditions.…

## Students' thinking process in solving combination problems. - Eric

This study aims to explain the thinking process of students in solving combination problems considered from assimilation and accommodation.…

## Permutation & Combination Problems & Practice

In this lesson, we will practice solving various permutation and combination problems using permutation and combination formulas. We can continue.…

## Combination Permutation Calculator - Stat Trek

Thus, 210 different 3-digit numbers can be formed from the digits 1, 2, 3, 4, 5, 6, and 7. To solve this problem using the Combination and Permutation Calculator.…

## Combination - Art of Problem Solving

A combination is a way of choosing $r$ objects from a set of $n$ where the order in which the objects are chosen is irrelevant. We are generally concerned with.…

## Combinations - Formula & Examples - Probability Formula

Also, there is no repetition taken in the concept of combinations. They are. Combination problems are given below Example 1 In a. Solution The possible number of ways for finding three names out of ten from the box is C 10, 3 = 10!3!7.…