Question 141

A multiple choice examination consists of 20 questions. The scoring is +5 for each correct answer, —2 for each incorrect answer, and 0 for each unanswered question. A student's score on the examination is 48. The maximum number of questions he could have answered correctly is

Solution

Let questions answered correctly = $$x$$ and unanswered questions = $$y$$, => incorrect questions = $$(20-x-y)$$

According to ques,

=> $$5x-2(20-x-y)=48$$

=> $$7x+2y=88$$

Since, sum of 2 positive numbers is positive, and 84 is the nearest multiple of 7 (when $$y=2$$)

=> $$7x=84$$ => $$x=12$$

Thus, maximum number of questions answered correctly = 12

=> Ans - (B)

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