A batch of 30 students took an intelligence test in an institution. 20 of them scored an average of 75 marks and the remaining students scored an average of 87 marks. What is the average score of the entire batch of students?
Explanation:
Total marks of all 30 students = 20 × 75 + 10 × 87 = 2370
Average marks of all 30 students = 2370/30 = 79.
Hence, option (a).