Question 980797
This is pretty straight forward:
...
The first slot can be any of the four available digits, 0, 1, 2, or 3
...
The second slot has the same digits available, but you can't repeat the digit from the first slot, so three available choices...
...
The third slot is like the second, it has the same four digits on the dial, but one of them is used in the prior setting, so it is unavailable in this slot...
...
To compute the number of available combinations to set:
...
4 x 3 x 3 = 36 possible combinations