Final answer:
The average weight of the girls in Class 6B is 36 kg.
Step-by-step explanation:
To find the average weight of the girls in Class 6B, we need to subtract the total weight of the boys from the total weight of the class. Let's assume the total weight of the class is T kg. According to the given information, there are 28 students in the class and their average weight is 40 kg. Therefore, the total weight of the class is 28 * 40 = 1120 kg.
We also know that there are 16 boys in the class, and the average weight of the boys is 43 kg. Therefore, the total weight of the boys is 16 * 43 = 688 kg.
To find the total weight of the girls, we can subtract the total weight of the boys from the total weight of the class: T - 688 = 1120 - 688 = 432 kg.
Since the number of girls in the class is equal to the number of students minus the number of boys (28 - 16 = 12), we can find the average weight of the girls by dividing the total weight of the girls by the number of girls: 432 / 12 = 36 kg.
Therefore, the average weight of the girls in Class 6B is 36 kg. Option a) 37.7 kg is the closest option, but it is not the correct answer. The correct answer is a) 36 kg.