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.

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.

Richard A. Edwards, Permutations, Combinations, and Circular Seating Arrangements, The Mathematics Teacher, Vol. 110, No. 3 (October 2016), pp. 232-236 ...

This example, from Keith Soper at Merck, illustrates the exact permutation Cochran-Armitage test carried out on permutation resamples. In the following data set, the 0s represent failures and the 1s ...