a. if the characters should not repeat? b. if the characters repeat? c. if the first 3 characters are numbers and the last 3 characters are letters, which are all distinct?

Users of the online system for a Bank are required to set a password that is 10 character-long. Each character can be a letter, a 1-digit number, or a symbol from the list: !, @, #, &, % How many passwords are possible if there is no distinction between upper case and lower case letters? (Not Case-sensitive) How many passwords are possible if the first and last digits have to be numbers?

For a Halloween party, each guest can choose from the 6 different kinds of candy to have in a prize bag. If any number of candy types can be chosen, how many candy type combinations are possible?

A standard-issue 2020 New Jersey license plate had one letter, then two digits, followed by three letters. New Jersey DOO SPA Garden State These plates were not allowed to have letters D, T, or X in the fourth position, or the letters I, O, or Q in any position. With these restrictions, how many different license plates were possible in 2020?