a) Set A lists the people in an organization who are eligible to be President or Treasurer. In how many ways can the two elected positions be filled? A={Lisa, Mimi, Ben, Kelly, Dan}. b) Joe doesn't like to spend a lot of time unlocking his phone. If he plans to use a two letter code, how many different codes can be made using only the letters in Set B? B={the first 7 letters of the alphabet}