Permutations Examples on Alphabets

In this class, We discuss Permutations Examples on Alphabets.

The reader should have prior knowledge of permutation formulae. Click here

Example:

Given alphabets A, B, C, D, E, F, G, and H.

1) How many permutations contain the string CDE.

A sample string ABCFDEGH.

The sample does not contain CDE.

To obtain CDE together, we need to take CDE as a single element.

Total elements are A, B, CDE, F, G, and H.

Six elements should be placed in six positions in 6! ways.

2) How many strings contain AB and FG.

AB and FG should be taken as elements.

Total elements are AB, C, D, E, FG, and H.

Six elements should be placed in six positions in 6! ways.

3) The number of permutations containing the string ABC and CDE.

ABC and CDE can be obtained by taking ABCDE as a single element.

ABCDE, F, G, and H are the elements.

Four elements can be filled in four positions in 4! ways.

4) The number of permutations containing string ABC and BDE.

We can not have two strings, ABC and BDE.

There are zero possible ways.