An experimental drug was given to a sample of hospital patients with an unknown sickness. Of the​ total, patients reacted​ favorably, reacted​ unfavorably, and were unaffected by the drug. Assume that this sample is representative of the entire population. If this drug is given to Mr. and Mrs. Rivera and their son​ Carlos, what is the probability that all three react​ favorably? (Assume​ independence.