10th class of 40 students took a Maths test. 25 students had an average score of 60. The other students had an average score of 80. What is the average score of the whole class?
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. 67.5.
Total score of the first 25 students = 25 × 60 = 1500
Remaining students = 40 - 25 = 15
Total score of the remaining 15 students = 15 × 80 = 1200
Average = (1500 + 1200)/40 = 2700/40 = 67.5
Therefore, the average score of the whole class is 67.5.