Hi, i have a test tommorow and I can't seem to figure out these two problems: 1. Atm codes: to use an automated teller machine, you generaaly must enter a four-digit code, using 0-9. How many four digits codes are possible if repetition of digits is permitted? 2. Licence plate: a license plate is to have uppercase letters or digits. Determine the number of license plates possible if repetition is permitted and if any position can contain either a letter or digit with the expection that the first position caanot the letter o or the number 0. Can some one help me?