As Part of Pharmaceutical Testing for Drowsiness as a Side

Short Answer

As part of pharmaceutical testing for drowsiness as a side effect of a drug, 200 patients are randomly assigned to one of two groups of 100 each. One group is given the actual drug and the other a placebo. The number of people who felt drowsy in the next hour is recorded as a. What is the probability that a randomly picked patient in the study feels drowsy in the next hour?
B) What is the probability that a randomly picked patient in the study takes the placebo or feels drowsy in the next hour?
C) Given that the patient was given the drug, what is the probability that he or she feels drowsy in the next hour?
D) Is whether a patient feels drowsy independent of taking the drug? Explain using probabilities.