Question 1177814

Five choices for the hundreds digit {1,4,5,8,9}.
Five choices for the tens digit {five digits, the four not chosen above, + "0"}.
Four choices for the ones digit {the four remaining digits}.<br>

5*5*4 = 100<br>


The above assumes a true 3-digit number (in the purest numerical sense, "014" would not be a 3-digit number because it is normally written "14").   However, in some applications (keypad lock for example, 014 could be combination).  If leading zero is allowed, you get 6*5*4...