How many passwords are there if a password must be no more than 5 characters long, the characters must be lower case letters, and the first character cannot be an a.
If letters can be repeated, we have .... 25 x 26^4 = 11,424,400
If letters cannot be repeated, we have...... 25 x 25 x 24 x 23 x 22 = 7,590,000