Question 53

The average weight of boys in a class is 30 kg and the average weight of girls in the same class is 20 kg. If the average weight of the whole class is 23.25 kg, what could be the possible strength of boys and girls respectively in the same class ?

Solution

Let the number of boys = $$x$$ and girls = $$y$$

=> Total weight of boys = $$30x$$

Total weight of girls = $$20y$$

Acc to ques,

=> $$30x + 20y = 23.25 (x + y)$$

=> $$30x + 20y = 23.25x + 23.25y$$

=> $$6.75x = 3.25y$$

=> $$\frac{x}{y} = \frac{325}{675} = \frac{13}{27}$$

Hence, possible strength of boys and girls respectively can be 13 and 27

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