In an entrance exam of 200 objective questions, a student scores +1 for each…
2024
In an entrance exam of 200 objective questions, a student scores +1 for each correct answer, –1/4 for each wrong answer, and –1/2 for each unanswered question. He attempts 160 questions and scores 100 points.
How many questions did he answer correctly?
Answer: D. 128 — Let x be the number of correct answers. He attempts 160 questions, so wrong = 160 - x and unanswered = 200 - 160 = 40. Total score equation: x - (1/4)(160 -…
- A.
132
- B.
126
- C.
139
- D.
128
Attempted by 21 students.
Show answer & explanation
Correct answer: D
Let x be the number of correct answers.
He attempts 160 questions, so wrong = 160 - x and unanswered = 200 - 160 = 40.
Total score equation:
x - (1/4)(160 - x) - (1/2)(40) = 100
Expand the terms: x - 40 + x/4 - 20 = 100
Combine like terms: x + x/4 - 60 = 100
Add 60 to both sides: x + x/4 = 160
Multiply both sides by 4: 5x = 640, so x = 128
Answer: 128 correct answers.