Question

How many permutations for a 7 characters in length string, which contains all following letters R, X, S, Y, T, Z, U, has either the string 'RXS' or string 'ZU' in the 7 characters string?

Answer 1

Following are the solution to this question:

Step-by-step explanation:

In the following forms, RXS can appear:

`R X S \_ \_ \_ \_` it may look like that really,
`4 * 3 * 2 * 1` forms = 24 may construct the remainder of its letters.

`\_ R X S \_ \_ \_` it may look like that really,
`4 * 3 * 2 * 1` forms = 24 may construct the remainder of its letters.

`\_ \_ R X S \_ \_` it may look like that really,
`4 * 3 * 2 * 1` forms = 24 may construct the remainder of its letters.

`\_ \_ \_ R X S \_` it may look like that really,
`4 * 3 * 2 * 1` forms = 24 may construct the remainder of its letters.

`\_ \_ \_ \_ R X S` it may look like that really,
`4 * 3 * 2 * 1` forms = 24 may construct the remainder of its letters.

And we'll have a total of
`24 * 5 = 120` permutations with both the string RXS.

In the following forms, UZ can appear:

`U Z \_ \_ \_ \_\ _` They can organize your remaining 5 characters through 5 categories! Procedures
`= 5 * 4 * 3 * 2 * 1 = 120`

`\_ UZ \_ \_ \_ \_` They can organize your remaining 5 characters through 5 categories! Procedures
`= 5 * 4 * 3 * 2 * 1 = 120`

`\_ \_ U Z \_ \_ \_`They can organize your remaining 5 characters through 5 categories! Procedures
`= 5 * 4 * 3 * 2 * 1 = 120`

`\_ \_ \_ U Z \_ \_`They can organize your remaining 5 characters through 5 categories! Procedures
`= 5 * 4 * 3 * 2 * 1 = 120`

`\_ \_ \_ \_ U Z \_` They can organize your remaining 5 characters through 5 categories! Procedures
`= 5 * 4 * 3 * 2 * 1 = 120`

`\_ \_ \_ \_ \_ U Z` They can organize your remaining 5 characters through 5 categories! Procedures
`= 5 * 4 * 3 * 2 * 1 = 120`

There may be
`120 * 6 = 720` ways of complete permutations.