How many 5 string passwords can be formed?

Question

The string can be made up of lowercase letters or digits. Contain at most 2 lowercase letters and no repeated digits.

Answer 1

Password composed of 2 lower case letters and 3 different digits implies

variations of password by different letters = ²⁶P₂ = (26 x 25) = 650

variations of password by different digits = ¹⁰C₃ = (10 x 9 x 8)/(3 x 2 x 1) = 120

Therefore number of different passwords = 650 x 120 = 78000

I hope this helps.

Sincerely,

Shailesh (Sky) Kadakia, Expert Tutor WYZANT.