Ames surveyed people at school and asked whether they bring their lunch to school or buy their lunch at school more often. The results are shown below. Bring lunch: 46 males, 254 females
Buy lunch: 176 males, 264 females

The events "male” and "buys lunch” are not independent because

P(buys lunch | male) = P(male) = 0.4.
P(male | buys lunch) = P(male) = 0.3.
P(buys lunch | male) = 0.3 and P(male) = 0.4.
P(male | buys lunch) = 0.4 and P(male) = 0.3.