A lock has a 3-number code made up of 25 numbers. If none of the numbers are allowed to repeat, how many different ways can you choose three different numbers in order for a unique code?
There are 25 choices for the first number, 24 choices for the second number (since it cannot be the same as the first), and 23 choices for the third number (since it cannot be the same as the first or second). Therefore, the total number of ways to choose three different numbers in order is 25 * 24 * 23 = <<25*24*23=13800>>13,800.
