1(5). One library allows borrowing at most 3 books at a time. Let random variable be the number of books people borrow from the library. The probability that people does not borrow any books is 0.05; the probability that people borrow one, two, three books are 0.2, 0.4, 0.35, respectively. 1(3). Find mean and variance of the number of books people borrow. 2(2). Find the probability that people borrow at least two books