Fast please please

License plates in a particular state are to consist of 3 digits followed by 3 uppercase letters a) How many different license plates can there be in this state if repetition of letters and numbers is permitted? b) How many different license plates can there be in this state if repetition of letters and numbers is not permitted? c) How many different license plates can there be in this state if the first and second digits must be odd, and repetition of letters and numbers is not permitted? d) How many different license plates can there be in this state if the first digit cannot be 2, and repetition of letters and numbers is not permitted? a) There are different possible license plates if repetition of numbers and letters is permitted b) There are different possible license plates if repetition of numbers and letters is not permitted c) There are different possible license plates if the first and second digits must be odd, and repetition of letters and numbers is not permitted d) There are different possible license plates if the first digit cannot be 2, and repetition of letters and numbers is not permitted