53 % of all violent felons in the prison system are repeat offenders . If 43 violent felons are randomly selected , find the probability that

a . Exactly 21 of them are repeat offenders .

b . At most 24 of them are repeat offenders .

c . At least 24 of them are repeat

. d . Between 17 and 21 ( including 17 and 21 ) of them are repeat . offenders .

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