I am trying to solve this using a contingency table however I can not find how to solve It.

Question 1 Suppose that in a certain election, all registered voters will cast a ballot or not cast a ballot. In addition, all registered voters have a clear preference for either Candidate A or Candidate B in a certain race in the election (there are no other candidates). The probability that a registered voter prefers Candidate B and will cast a ballot is 25%. The probability that a registered voter prefers Candidate A and will not cast a ballot is 30%. The probability that a registered voter prefers Candidate A or will cast a ballot is 75%. Given a random registered voter, what is the probability that the voter will not cast a ballot? Question 2 Given a random registered voter who did not cast a ballot, what is the probability that this voter preferred Candidate B