Safe combinations are permutations because the order of the numbers matters to open the safe. An anagram where different words come from the same root word is another example.

Permutations and combinations are important concepts in mathematics and are frequently tested in exams like the Common Admission Test.

Problems on Permutations and Combinations : CAT Quantitative Aptitude This article takes you through some of the applications of the concepts that may be tested in Permutations and Combinations.

Combination of encryption and decryption for secure communication is an application. Here, the authors are using permutation and substitution technique to make the people’s data more secure.

After previously discussing permutations, Dr. James McCaffrey of Microsoft Research uses step-by-step examples and full code presentations to explore combinations.