The average weight of 30 students in a class is 45 kg. If the average weight of the 10 heaviest students is 55 kg, what is the average weight of the remaining 20 students?

✓ Correct Answer: Option B

Total weight of 30 students = 30 * 45 = 1350 kg. Total weight of 10 heaviest students = 10 * 55 = 550 kg. Weight of the remaining 20 students = 1350 - 550 = 800 kg. Average weight of remaining 20 students = 800 / 20 = 40 kg.