A class of 45 students weighs themselves. 10 students have an average weight of 55 kg, and the remaining students have an average score of 60 kg. Thus, the average weight (in kg) of the whole class is: (rounded off to the nearest integer)

Correct option is A

Given:
Total students = 45
Average weight of 10 students = 55 kg
Remaining students = 45 - 10 = 35
Average weight of 35 students = 60 kg
Formula Used:
​$$\text{Average weight} = \frac{\text{Sum of weights of all students}}{\text{Total number of students}}$$​​
Solution:
Sum of weights of 10 students = 10 × 55 = 550 kg
Sum of weights of 35 students = 35 × 60 = 2100 kg
Total weight = 550 + 2100 = 2650 kg
Total students = 45
=> Average weight = $$\frac{2650}{45}$$​ ≈ 59 (rounded off to nearest integer)