A New MedicineIn Exercises 77-80, a new medicine was given to a sample of 100 hospital patients. Of the total, 70 patients reacted favorably, 10 reacted unfavorably, and 20 were unaffected by the drug. Assume that this sample is representative of the entire population. If this medicine is given to Mr. and Mrs. Rivera and their son Carlos, what is the probability of each of the following? (Assume independence.)

1. Mrs. Rivera reacts favorably.
2. Mr. and Mrs. Rivera react favorably, and Carlos is unaffected.
3. All three react favorably.
4. None of the three reacts favorably.