The number of possible 3 - digit codes would be 900.
"A combination is a way of selecting items from a collection."
For given situation,
It is a three digit code with 0 can't be the first digit.
This means the for this combination first digit can takes values from 1 - 9 and the second and third digits can take values from 0 - 9.
So, the number of possible 3 - digit codes would be,
9 × 10 × 10 = 900
Therefore, the number of possible 3 - digit codes would be 900.
Learn more about permutation and combination here:
https://brainly.com/question/13387529
#SPJ2