Civil Services Prep

Prelims 2026 · CSAT / Quantitative Aptitude · Question 38

In an objective type question paper, 5 marks are awarded for a correct answer and 2 marks are deducted for a wrong answer. A student attempted all the questions and got a score of 69. Had he been awarded 4 marks for a correct answer and 1 mark deducted for a wrong answer, he would have scored 84. How many questions were there in the question paper?<br/>

  1. 99
  2. 81
  3. 84
  4. 79

Answer

81

Let correct answers = c and wrong answers = w. Then 5c - 2w = 69 and 4c - w = 84. Subtracting gives c - w = -15, so w = c + 15. Substitute into 4c - w = 84: 4c - (c + 15) = 84, so 3c = 99, hence c = 33 and w = 48. Total questions = 33 + 48 = 81.

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