In a class of 55 students there are 34 girls. The average weight of these girls is 51 Kg and average weight of the full class is 55.2 kgs. What is the average weight of the boys of the class?
Total number of students = 55 and number of girls = 34
=> Number of boys in class = 55 - 34 = 21
Average weight of girls = 51 kg
=> Total weight of girls = $$51 \times 34 = 1734$$ kg
Similarly, total weight of full class = $$55.2 \times 55 = 3036$$ kg
=> Total weight of boys = 3036 - 1734 = 1302 kg
$$\therefore$$ Average weight of boys = $$\frac{1302}{21} = 62$$ kg
=> Ans - (A)
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