Given that randomly chosen person eats breakfast almost everyday, what is the probablility that the person also buys cereal at least once a month? 11/64 11/53 53/64 53/57

Sample size who buy cereal at least once a month = {53+4}=57 (all possible outcomes)
Sample size who have breakfast AND buy cereal = {53} = favorable outcome

P(Breakfast AND cereal) = 53/57