In some applications, a passcode consisting of some number of digits is required (for example, a PIN). Using the number-to-letter conversion on a telephone, a. What passcode corresponds to the...

In some applications, a passcode consisting of some number of digits is required (for example, a PIN). Using the number-to-letter conversion on a telephone,

a. What passcode corresponds to the password "hello"?

b. Find as many passwords as you can that correspond to the passcode 5465, where each password is an English dictionary word.