4.69 Suppose the probability of exposure to the flu during an epidemic is 0.6. Experience has shown that a serum is 80% successful in preventing an inoculated person from acquiring the flu if exposed. A person not inoculated faces a probability of 0.90 of acquiring the flu exposed. Two persons, one inoculated and one not, are capable of performing a highly specialized task in a business.

Assume that they are not at the same location, are not in contact with the same people, and cannot expose each other. What is the probability that at least one will get the flu?

4.70 Two gamblers bet $1 each on the successive tosses of a coin. Each has a bank of $6.

a What is the probability that they break even after six tosses of the coin?

b What is the probability that one player, say Jones, wins all the money on the tenth toss of the coin?