In an examination, a student scores 4 marks for every correct answer and loses 1 mark for every wrong answer. If he attempts all 75 questions and secures 125 marks, the number of questions he attempts correctly, is ?
35
40
42
46
Explanation:
Let the number of correct answers be x.
Then numbers of incorrect answers will be 75 - x
We get 4x - (75 - x) × 1 = 125
On solving the equation we get x= 40.