According to' the U.S. Census Bureau, in 2011 about 10% of persons between 25 and 39 years

Question:

According to' the U.S. Census Bureau, in 2011 about 10% of persons between 25 and 39 years old live alone. For a random sample of size n, use the binomial table to find the probability of
(a) 1 or fewer persons living alone when n = 12.
(b) 2 or more persons living alone when n = 12.
(c) Find the expected number when n = 12.
(d) 1 or fewer persons living alone when n = 20.