Of 100 people surveyed, 60 like coffee, 45 like tea, and 25 like both. What is the probability that a randomly selected person likes…

Use the addition rule: $P(\text{coffee or tea})=P(\text{coffee})+P(\text{tea})-P(\text{both})=0.60+0.45-0.25=0.80$, choice C. The people who like both were counted twice, once in each group, so they must be subtracted once. Equivalently, $35$ like only coffee, $20$ like only tea, and $25$ like both, which totals $80$ out of $100$. Choice D ($1.05$) forgets to subtract the overlap, and a probability cannot exceed $1$. Choice A ($0.60$) counts only coffee drinkers. Choice B ($0.70$) is $0.45+0.25$, which leaves out the coffee-only group.