Do you have a test coming up that includes questions on permutations and combinations? If so, don’t panic! We’re here to help. In this blog post, we will discuss the basic concepts of permutations and combinations. We’ll also provide some tips to give you master these topics. Good luck!
Permutations and combinations are two of the most fundamental concepts in mathematics. They are often used in problem solving, and understanding them is essential for success on the GRE.
A Permutation Is An Arrangement Of Objects In Which The Order Is Important. For Example, If You Have A Group Of Three People, There Are Six Possible Permutations:
Person 1, Person 2, Person 3
Person 1, Person 3, Person 2
Person 2, Person 1, Person 3
Person 2, Person 3, Person 1
Person 3, Person 1, Person 2
Person 3, Person 2, Person 1
Notice that the order of the people matters in this case. If we were to list all of the possible permutations of a group of four people, there would be 24 of them.
A combination is a selection of objects in which the order is not important. Using the same example from before, if we have a group of three people, there are only three possible combinations:
Person 1 and Person 2
Person 1 and Person 3
Person 2 and Person 3
Notice that the order doesn’t matter in this case. If we were to list all of the possible combinations of a group of four people, there would be six of them.
Here Are Some Tips To Help You Master These Concepts.
- Make sure you understand the difference between permutations and combinations. When solving problems, it is important to be able to determine whether the order of the objects matters or not.
- Practice using the formula nCr = n!/(r!(n-r)!). This will come in handy when you need to calculate the number of possibilities.
- Solve as many practice problems as you can. The more you practice, the better you will become at solving these types of problems.
We hope this blog post has been helpful. Best of luck on your upcoming test!
Achievable’s GRE prep course is designed to help you feel less overwhelmed by the amount of content covered. Become an exam ace with a course that provides everything you need. We invite you to visit our website to learn more and sign up!