Question 653618
Since there are 5 odd digits you can select them as follows:
There are 5 choices first the first number,
then 4 choices for the second number, 
and 3 choices for the third, giving you
5*4*3 or 60 possible permutations of 3 different odd digits.
Tacking these 60 numbers onto your 52 letters results in
52*60 or  3120 choices for the custumer.