There are 2 sections A and B in a class, consisting of 30and 20 students respectively. If the average weight of section A is 40kg and that of section B is 35kg, Find the average of the whole class?
Select the correct option
A) 35 kg
B) 37 kg
C) 42 kg
D) 38 kg
E) 29.78 kg

Rationale: "total weight of 36 + 44 students = 30 * 40 + 20 * 35 = 1900 average weight of the class is = 1900 / 50 = 38 kg answer is d"
Answer: D