In a class there are 50 students. Their average weight is 45 kg. When a student leaves the class, the average is reduced by 100 g. Find the weight of the student who left the class.
Note
Total weight of 50 students = (45 × 50) kg = 2250 kg
The average weight of 49 students = (45 kg - 100 g) = 44.9 kg.
Total weight of 49 students = (44.9 × 49) kg = 2200.1 kg.
∴ Weight of the student who left the class = (2250 – 2200.1) = 49.9 kg.