Permutations and Combinations

 Do you know that the particular areas that have extensive applications of com- binatorics such as permutations and combinations include: communication networks, cryptography and network security; computer architecture; electrical engineering; computational molecular biology; languages both natural and computer; pattern analysis  A permutation is used for the list of data (where the order of the data matters) and the combination is used for a group of data (where the order of data doesn't matter).  * GCSE, IGCSE, AP, PSAT, and IB - Exam Style Questions which covers all the related concepts required for students to unravel any International Exam Style Permutations and Combinations Questions  * Learner will be able to: Recognise and distinguish between a permutation case and a combination case Know and use the notation n! (With 0! = 1), and the expressions for permutations and combinations of n items taken r at a time Answer simple problems on arrangement and selection Note: cases with repetition of objects or with objects arranged in a circle, or involving both permutations and combinations, are excluded not applicable in GCSE/IGCSE Combinatorics is used frequently in computer science to obtain formulas and estimates in the analysis of algorithms. A mathematician who studies combinatorics is called a combinatorialist