Question

The ratio of the number of boys and girls in a class is 5 : 7. The average weight of boys is 56 kg and that of girls is 50 kg. What is the average weight (in kg) of all the boys and girls in the class?

• A. 54.1
• B. 53.2
• C. 52.5
• D. 51.8

Answer 1

Answer:

C. 52.5

Let the number of boys and girls be 5x and 7x Total weight of the boys = 5x × 56 = 280x Total weight of the boys = 7x × 50 = 350x Total weight of the boys and girls = 280x + 350x = 630x Now the average of boys and girls = 630x/12x = 52.5