A lock has a 3-number code made up of 26 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?
Since none of the numbers are allowed to repeat, for the first number, we have 26 options. For the second number, there are 25 remaining options. Finally, for the third number, there are 24 remaining options. Thus, the total number of different ways to choose three different numbers is $26 \times 25 \times 24 = \boxed{15,\!600}$.
