The average score of 40 students is 72. The average score of another 20 students is 78. Find the average score of all 60 students.
Show answer & explanation
Correct answer: B
Explanation
Total marks of 40 students = 40 × 72 = 2880
Total marks of 20 students = 20 × 78 = 1560
Total marks of all 60 students:
2880 + 1560 = 4440
Average:
4440 ÷ 60 = 74