Passage Summary: A school district hired 30% more teachers, but the average class size didn't drop at all.

Reasoning: The school system increased its teacher count by 30 percent, yet the average number of students per teacher remained exactly the same.

Analysis: This is a mathematical inference question. If the number of teachers (the denominator in the ratio) went up by 30% and the ratio stayed the same, the number of students (the numerator) must have also increased by exactly 30%. If the student population had stayed the same or grown by a smaller percentage, the ratio would have decreased. Look for an answer that acknowledges the proportional increase in the student population to match the teacher increase.