More Lessons: http://www.MathAndScience.com Twitter: https://twitter.com/JasonGibsonMath In this lesson, you will learn how to calculate the combinations for a sequence of data and determine how the number of combinations differ from the permutations that we learned in a previous lesson. a combination is the number of ways objects can be ordered without regard to the order of selection of the objects. In other words, a selection of all or part of a set of objects or numbers, without regard to the order in which they are selected from the pool. For example, if we have 3 letters but only take them two at a time, we can calculate how many combinations in which we can make the selections.