Chapter 0.4, Problem 11E

To determine

the numbers of passwords are allowed if no digit may be used more than once.

Answer to Problem 11E

The numbers of passwords are allowed if no digit may be used more than once are 60480.

Explanation of Solution

Given information :

Abby is registering a website. She must select a password containing six digits from 1 to 9 to be able to use the site.

In the given event,

The numbers of passwords are allowed if no digit may be used more than once is given by,

  $9\times 8\times 7\times 6\times 5\times 4=60480$

So, the numbers of passwords are allowed if no digit may be used more than once are 60480.