50% of all violent felons in the prison system are repeat offenders. If 30 violent felons are randomly selected, find the probability that a. Exactly 13 of them are repeat offenders. b. At most 15 of them are repeat offenders. c. At least 14 of them are repeat offenders. d. Between 12 and 17 (including 12 and 17) of them are repeat offenders. Hint