According to a study, 80 % of adult smokers started smoking before 21 years old. 9 smokers 21 years old or older are randomly selected, and the number of smokers who started smoking before 21 is recorded. Round all answers to 3 decimal places.

1. The probability that at least 5 of them started smoking before 21 years of age is
2. The probability that at most 7 of them started smoking before 21 years of age is
3. The probability that exactly 2 of them started smoking before 21 years of age is