If two letters were selected and the order of selection are important then the following 20 outcomes are possible as AB, BA, AC, CA, AD, DA, AE, EA, BC, CB, BD, DB, BE, EB, CD, DC, CE, EC, DE, ED.įor combinations, k elements are selected from a set of n objects to produce subsets without bothering about ordering. The conceptual differences between permutations and combinations can be illustrated by having all the different ways in which a pair of objects can be selected from five distinguishable objects as A, B, C, D, and E. For example, if we have two alphabets A and B, then there is only one way to select two items, we select both of them. On the other hand, the combination is the different selections of a given number of objects taken some or all at a time. For example, if we have two letters A and B, then there are two possible arrangements, AB and BA. Thus Permutation is the different arrangements of a given number of elements taken some or all at a time. This selection of subsets is known as permutation when the order of selection is important, and as combination when order is not an important factor. Normally it is done without replacement, to form the subsets. Permutations and combinations are the various ways in which objects from a given set may be selected.

2 Solved Examples Permutation and Combination Formula What are permutations and combinations?

Permutation combination formula