A highway agent sampled cars going from one state to a neighboring state. In his report, he indicated that of the 78 cars sampled, 31 cars were driven by women, 52 cars were sport-utility vehicles, 44 cars had two or more passengers, 26 cars were driven by women in sport-utility vehicles, 24 cars were driven by women and had two or more passengers, 21 cars were sport-utility vehicles and had two or more passengers, and 15 cars were driven by
women in sport-utility vehicles and had two or more passengers. After his supervisor reads the report, she explains to the agent that he made a
mistake. Explain how his supervisor knew that the agent's report contained an error.