In an examination, a student scores 6 marks for every correct answer and loses 4 marks for every wrong answer. If he attempted 80 questions and obtained 310 marks, how many questions did he attempt correctly?

59 65 63 67

63

If all questions are correct, then max marks =80 × 6 = 480 If all questions are wrong, then max marks = 80 × 4 = - 320 Now, lets Use allegation method: