A candidate takes a test and attempts all the 100 questions in it. While any correct answer fetches 1 mark, the wrong answers are penalised as follows; one-tenth of the questions carry 1/10 negative marks each, one-fifth of the questions carry 1/5 negative marks each and the rest of the questions carry 1⁄2 a negative mark each. Unattempted questions carry no marks. What is the difference between the maximum and the minimum marks that he can score? Correct Answer 140 GIVEN: For minimum marks: one-tenth questions = 1/10 negative mark each one-fifth questions = 1/5 negative mark each Rest = 1/2 negative mark each CONCEPT: First for maximum marks let's assume he answers all questions correctly. CALCULATION: Maximum marks = 100. so one tenth ,one fifth of 100 questions are 10 and 20 questions respectively. Negative marks for 30 questions = -(10/10) + (20/5) = -5 70 questions carry = (70 × 1/2) = 35 negative marks. Total negative marks = (35 + 5) = 40 marks ∴ difference = 100 - (-40) = 140