that a patient suffering from a certain disease 80% survive a)what is the probability that of the 6 randomly selected patients at most 2 will survive?...

3)hospitial records show that a patient suffering from a certain disease 80% survivea)what is the probability that of the 6 randomly selected patients at most 2 will survive?b)what is the probability that of 6 randomly selected patients at least 2 will survivec)find the probability that if 100 patients are randomly selected more than 75 of them will survive use normal approximation to the binomial distribution to determine the answer if this probability cannot be determined explain why