In 1970, 92% of American 30-year-olds earned more than their parents did at age 30 (adjusted for inflation). In 2014, only 51% of American 30-year-olds earned more than their parents did at age 30.

(a) What is the probability a randomly selected 30-year-old in 1970 earned more than his or her parents at age 30?
(b) What is the probability that two randomly selected 30-year-olds in 1970 earned more than their parents at age 30?
(c) What is the probability that out of ten randomly selected 30-year-olds in 1970, at least one did not earn more than his or her parents at age 30?
(d) What is the probability that out of ten randomly selected 30-year-olds in 2014, at least one did not earn more than his or her parents at age 30?