SOLUTION: You need to have a password with 4 letters followed by 2 even digits between 0 and 9, inclusive. If the characters and digits cannot be used more than once, how many choices do yo

We have 26 letters and 5 digits 0, 2, 4, 6, and 8 in our possession.



Any of 26           letters in the 1-st position;

any of 25 remaining letters in the 2-nd position;

any of 24  --------- " ----------- 3-rd position;

any of 23  --------- " ----------- 4-th position;


any of 5             digits in the 5-nd position;

any of 4  remaining  digits in the 6-nd position.



In all, 26*25*24*23*5*4 = 7176000 different codes are possible.