It is known that 60% of patients recovering after operations are from heart operations. If 7 patients undergo heart operations, find the probability that

a) Less than 3 patients recover;

b) Between 2 and 5 patients recover (inclusive);

c) If 2% of patients recover from heart operations are then

infected by bacteria, what is the probability that in a random sample of 150 patients, less than 8 are being infected?