GATE 2015 EE – Question 10
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?
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Correct answer: (C) 6.795
Explanation
Each row sums to 44 students, so the class has 44 students. Total marks obtained $= 21(2) + 15(3) + 11(1) + 23(2) + 31(5) = 42 + 45 + 11 + 46 + 155 = 299$. The average is $\frac{299}{44} = 6.795$.