Determine the number of arrangements or ways to select a small number of items is a relatively simple task. With a large number of items, however, the process can become very complicated.

In fact, combinatorics is a field of mathematics dedicated solely to the science of counting.

Determine the number of arrangements or ways to select a small number of items is a relatively simple task. With a large number of items, however, the process can become very complicated. For example, think about all the possible combinations of numbers in lottery tickets or all the different seating arrangements at a big event.