Question

Determine the number of passwords comprised of 3 upper case, 3 lower case letters, 4 digits, and 2 special characters (these include #$&*()!?^[], so 11 in total)

Answer 1

since there are 26 letters and 3 are to be chosen and the letters can be repeated- 26*26*26

since there are 26 letters and 3 are to be chosen and the letters can be repeated- 26*26*26

since there are 10 digits and 4 are to be chosen and the digits can be repeated-10*10*10*10

since there are 11 special characters are to be chosen and the letters can be repeated-11*11

= 26^6*10^4*11^2

now these can be arranged in 12 spots so no. of arrangements = 12!

total no. of ways -26^6*10^4*11^2*12!