In an objective type test of 90 questions, 5 marks are allotted for every correct answer and 2 marks are…
In an objective type test of 90 questions, 5 marks are allotted for every correct answer and 2 marks are deducted for every wrong answer. After attempting all the 90 questions, a student got a total of 387 marks. What is the number of incorrect responses?
9
13
27
43
Solution
If all 90 answers were correct the score would be $90 \times 5 = 450$. Each wrong answer loses the 5 marks not earned plus a 2-mark penalty, i.e. 7 marks. Total reduction from maximum = $450 - 387 = 63$. Number of incorrect responses = $63 / 7 = 9$.