The average weight of a class of 39 students is 40 kg. When a new student is admitted to the class, the average decreases by 200 g. Find the weight of the new student.
Mean weight of 39 students = 40kg
Total weight of 39 students = 39×40 = 1560 kg
If a new student is admitted to the class, the average decrease by = 200g = 0.2 kg
So new average weight = 40 - 0.2 = 39.8kg
Total weight of 39 students and 1 new student = 39.8×40 = 1592 kg
Weight of new student = 1592 – 1560 = 32kg
Hence the weight of the new student is 32 kg.