Explanation
To find the number of schools where the tuition fee is less than four times the activity fee, we compare the tuition fee with four times the activity fee for each school.
For school P, the tuition fee is 120 and the activity fee is 24. Four times the activity fee is 4 × 24 = 96. Since 120 is not less than 96, school P does not satisfy the condition.
For school Q, the tuition fee is 60 and the activity fee is 12. Four times the activity fee is 4 × 12 = 48. Since 60 is not less than 48, school Q does not satisfy the condition.
For school R, the tuition fee is 210 and the activity fee is 45. Four times the activity fee is 4 × 45 = 180. Since 210 is not less than 180, school R does not satisfy the condition.
For school S, the tuition fee is 90 and the activity fee is 24. Four times the activity fee is 4 × 24 = 96. Since 90 < 96, school S satisfies the condition.
For school T, the tuition fee is 120 and the activity fee is 30. Four times the activity fee is 4 × 30 = 120. Since 120 is equal to and not less than 120, school T does not satisfy the condition.
Thus, only one school (S) meets the required condition.