Out of 100 students of the class 20 scored an average of 40 marks, 30 scored an average of 50 marks, 50% of the remaining scored an average of 60 marks and the rest scored 100 marks. Find the average marks scored by the students.

Correct Answer: 57
Total marks obtained: 20 * 40 = 800 30 * 40 = 1200 50% of the remaining = 50 * 50 / 100 = 25 20 * 60 = 1200 Remaining = 25. 25 * 100 = 2500 Total marks obtained = 800 + 1200 + 1200 + 2500 = 5700 Average marks = 5700 / 100 = 57