A class had to collect a fixed total amount through equal contributions from 30 students. When 5 students were absent, each present student had to pay 20 rupees more than the originally determined contribution. What was the total amount collected?

3000 rupees

Let the original contribution per student be x rupees. The total amount is therefore 30x. When 5 students were absent, the remaining 25 students each paid (x+20) rupees, so 30x = 25(x+20). Thus, 30x = 25x + 500, giving x = 100. Hence, the total amount is 30 × 100 = 3000 rupees, so option B is correct. Exam tip: In such problems, equate the total amount in the original and changed situations before solving for the per-student contribution.

This is a Class 10 Mathematics question. Chapter: Quadratic Equations. Topic: Word Problems and Applications.