Let F be the event that a customer is dissatisfied with the food at a restaurant and let S be the event that a customer is dissatisfied with the service. If P(F) = .15, P(S) = .40, and P(F ∩ S) = .10, what is the probability that a customer is dissatisfied with either the service or the food? a. .65 b. .55 c. .45 d. .10