Anjali started conducting weekly tests on Friday evening.
The marks in this test was used as a metric to judge
student's grasp over concepts discussed in this week. To
discourage students from making wild guesses, she
awarded +4 for correct responses and -1 for incorrect
responses. No marks were awarded or deducted for
unattempted questions.
The top scorer of last weekly test was Afzal. Afzal scored
200 marks. If he attempted all the 200 questions, then can
you tell us how many questions were answered correctly by
him.
Answers
Answer:
80
Step-by-step explanation:
Given,
Total question = 200
Marks awarded for correct responses = 4
Marks deducted for incorrect responses = -1
Solution,
Maximum marks which can be scored = 200×4
= 800
Minimum marks which can be scored = 200×-1
= -200
The number of questions answered correctly by the top scorer is 80
Given:
Marks awarded for correct responses = + 4
Marks awarded for incorrect responses = - 1
Total number of questions = 200
Marks of top scorer = 200
To Find: The number of questions answered correctly by the top scorer
Solution:
Let the number of correct answers = x and
let the number of incorrect answers = y
Since the top scorer's mark is 200 so we can write,
x × (+4) + y × (-1) = 200
⇒ 4x - y = 200 ...... (1)
Also the total number of questions including correct and incorrect is 200
∴ x + y = 200 ...... (2)
Solving equations (1) and (2), we get
x = 80
Hence, the number of questions answered correctly by the top scorer is 80.
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