21. one of them will get the u? (10 points) Suppose the probability of exposure to the u during epidemic is 0.6. Experience has shown that a serum if 80% successful in preventing an inoculated person from getting the u, if exposed to it. A person not inoculated faces a probability of 0.9 of getting the u if exposed to it. Assume that if a person is not exposed to the u, the person will not get the u. Suppose the event that an inoculated person gets the u is independent of the event that an uninoculated person gets the u. For any two persons, one inoculated and one not, what is the probability that at least