The number of students in a class who have answered correctly, wrongly, or not attempted each question in an exam, are listed in the table below. The marks for each question are also listed. There is no negative or partial marking.
Q.No. Marks Answered-Correctly Answered-Wrongly Not-Attempted 1 2 21 17 6 2 3 15 27 2 3 1 11 29 4 4 2 23 18 3 5 5 31 12 1
What is the average of the marks obtained by the class in the examination?
(A) 2.290
(B) 2.970
(C) 6.795
(D) 8.795
Answer: (C)
Explanation: There are total 44 students. This count can be obtained by adding last 3 entries of any row of given total.
Total marks = 2*21 + 3*15 + 1*11 + 2*23 + 5*31
= 299
Average marks = 299/44 = 6.795