Passage Summary: Every student lives in one of two buildings. Overall, 38% take night classes, but the percentage of night-class students in one building is lower than that overall average.

Reasoning: All students live in either Pulham or Westerville; 38% of the total student body takes night classes, but only 29% of the Westerville group takes night classes.

Analysis: This is a mathematical 'Must be True' question involving weighted averages. If you have two groups that make up a whole, and the average of the whole is 38%, one group cannot be below that average unless the other group is above it to balance things out. Since the Westerville group is below the 38% average (at 29%), the Pulham group must be above 38% to pull the total average up. Look for an answer that reflects this mathematical necessity regarding the Pulham residents.