a.Let the number of chocolate chips in a chocolate chip cookie have a Poisson distribution. We want the probability that a cookie of this type contains at least one chocolate chips to be greater than 0.99. Find the smallest value of the mean that the distribution can take.

b.At a used-book sale, 100 books are adult books and 160 are children's books. Seventy of the adult books are nonfiction while 100 of the children's books are fiction. Assume a book is selected at random, what is the probability that the book is an adult book or a children's nonfiction book?