In a class of 150 students (boys and girls only), the girls are 60. The average weight of boys is 52 kg and that of girls is 48 kg. What is the average weight (in kg) of the whole class?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 50.4.
Total number of students = 150
Number of girls = 60
Number of boys = 150 - 60 = 90
The average weight of boys = 52 kg
Total weight of boys = 90 × 52 = 4680 kg
The average weight of girls = 48 kg
Total weight of girls = 60 × 48 = 2880 kg
Average weight of class = (4680 + 2880)/150 = 7560/150 = 50.4 kg
Therefore, the average weight of the whole class is 50.4 kg.