Question 934575
8. Employees at a company are to be issued a computer ID code that consists of
three letters followed by two digits (0 to 9). How many ID codes are possible if
`
a. Repetition is allowed?
<pre>
26*26*26*10*10
</pre>
b. Letters may not repeat, but digits may repeat?
<pre>
26*25*24*10*10
</pre>
c. Neither letters nor digits may repeat?
<pre>
26*25*24*10*9

Edwin</pre>