In a school average weight of girls and boys are 30 kg and 36 kg. If number of girls is twice of the number of boys, then what will be the average weight of all the students in school?

32 kg

Lets assume number of boys be x

number of girls are 2x

Sum of weights of girls = 30 x 2x = 60x

Sum of weights of boys = 36 × x = 36x

Average weight of all students = \(\frac{60x + 36x}{3x}\) = 32