Correct option is C
Given:
Class 1: Number of students: 100 , Mean marks: 25
Class 2: Number of students: 50 , Mean marks: 70
Formula used:
Mean marks =
Solution:
Total marks for Class 1:
Total marks = 100 × 25 = 2500
Total marks for Class 2:
Total marks = 50 ×70 = 3500
Combined Classes:
Total number of students: 100 + 50 = 150
Total marks: 2500 + 3500 = 6000
Mean marks = = = 40
The mean marks obtained by the students of both classes taken together is 40.
Thus, correct answer is (c) 40