A class of 30 students appeared in a test. The average score of 12 students is 62, and that of the rest is 72. What is the average score of the class?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. 68.
Total number of students = 30
The average score of 12 students = 62
The total score of 12 students = 62 × 12 = 744
The number of rest of the students = 30 - 12 = 18
The average score of 18 students = 72 × 18 = 1296
The average score of 30 students = (744 + 1296)/30 = 2040/30 = 68
Therefore, the average score of the class is 68.