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Question
In a aptitude test of 100 questions, the marks awarded to each question is as follows:
+3 for correct answer
-1 for wrong answer
0 for unattempted question.
If alex scored 90 marks by attempting half of the questions, then how many questions did Alex attempted correctly?
In a aptitude test of 100 questions, the marks awarded to each question is as follows:
+3 for correct answer
-1 for wrong answer
0 for unattempted question.
If alex scored 90 marks by attempting half of the questions, then how many questions did Alex attempted correctly?
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Solution
The correct option is B 35
Marks obtained for 1 right answer = +3.
Marks obtained for 1 wrong answer = -1.
Total marks scored by Alex = 90.
Number of questions attempted = Half of 100 = 100 ÷ 2 = 50 questions.
Let number of correct answers be x.
Number of incorrect answers = (50 – x)
3x + (50 - x)(-1) = 90
3x - 50 + x = 90
4x = 90 + 50
4x = 140
x = 35
Therefore number of questions answered correctly = 35
Marks obtained for 1 right answer = +3.
Marks obtained for 1 wrong answer = -1.
Total marks scored by Alex = 90.
Number of questions attempted = Half of 100 = 100 ÷ 2 = 50 questions.
Let number of correct answers be x.
Number of incorrect answers = (50 – x)
3x + (50 - x)(-1) = 90
3x - 50 + x = 90
4x = 90 + 50
4x = 140
x = 35
Therefore number of questions answered correctly = 35
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