There are 2 sections A and B in a class, consisting of 50 and 40 students respectively. If the average weight of section A is 50kg and that of section B is 70kg, Find the average of the whole class?	Choose one
A) 50.78 kg
B) 49.32 kg
C) 61.67 kg
D) 58.88 kg
E) 70.89 kg

Rationale: "total weight of 50 + 40 students = 50 * 50 + 40 * 70 = 2500 + 2800 average weight of the class is = 5300 / 90 = 58.88 kg answer is d"
Answer: D