Question 883420
Repetitions are allowed except for the letter A. 
So then it must contain one A and repetitions of the other 5 letters is OK.
The A can be in one of three locations:(AXY),(XAY),(XYA)
So we'll find the total number for one and multiply by 3. 
{{{N=1*5*5=25}}}
{{{3N=3*25}}}
{{{3N=75}}} possible codes