In a class of 45 students, 30 are boys and remaining are girls. If the mean weight of girls is 45 kg and that of boys is 52 kg, then the mean weight of entire class (in kg) is nearest to
Total students = 45, Number of boys = 30 and number of girls = 15
=> Ratio of boys : girls = 2:1
Average weight of girls is 45 kg and that of boys is 52 kg
$$\therefore$$ Average weight of class = $$\frac{52(2)+45(1)}{2+1}$$
= $$\frac{149}{3}=49.67\approx50$$ kg
=> Ans - (C)