# Probability that adult smokers started smoking before

According to recent research, 80% of adult smokers started smoking before they were 18 years old. Suppose ten smokers are randomly selected and the number of smokers who started smoking before 18 is recorded.

A) Find the probability that exactly eight started smoking before turning 18 years of age.

B) Find the probability that more than eight started smoking before tuning 18 years of age.

C) Find the probability that eight or less started smoking before turning 18 years of age.

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#### Solution Preview

The number of smokers in the sample of 10 follows a binomial (10, 0.8) distribution. Hence,

a) ...

#### Solution Summary

The probability that adult smokers started smoking before the age of 18 is determined.

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