The total number of students in sections A and B of a class is 72. The ratio of the number of students in A and B is 7: 5. The average weight(in kg) of the students in section B is 20% more than that of the students in section A. If the average weight of all the students in the class is 52 kg, then what is the average weight (in kg) of the students in section B?

57.6

Avg. weight of students of class = 52

Avg. weight of students of class A = x

Avg. weight of students of class B = 1.2x

As per question

12 x 52 = 7x + 5 x (1.2x)

x = 48

So Avg.weight of section B = 57.6