64% of all violent felons in the prison system are repeat offenders. If 30 violent felons are randomly selected, find the probability that

a. Exactly 19 of them are repeat offenders.__________

b. At most 19 of them are repeat offenders._________

c. At least 18 of them are repeat offenders._________

d. Between 17 and 25 (including 17 and 25) of them are repeat offenders.____________