Question 984717
You have 3 letters and 3 numbers you can use.  Thats  a total of 6 choices
In the first position, you have 6 choices.
Since you can use repeats, in the second position you also have 6 choices.

so, 6 options for position 1 and 6 for position 2. 
{{{6 * 6 = 36}}}

You have 36 combinations you can make ... just like if you had 2 dice !