In a multiple-choice test, each question is followed by n options. What is the value of n?
(1) The test is designed in such a way that if a candidate appearing for the test, decides to mark the options for every question in a random manner, the candidate would expect to receive '0' marks in the test.
(2) For every correct answer, a candidate is awarded 1 mark and for every wrong answer, there are −1/3 marks assigned.
What's the best way to determine whether statement 1 is sufficient?
In a multiple-choice test, each question is followed by n op
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(1) The test is designed in such a way that if a candidate appearing for the test, decides to mark the options for every question in a random manner, the candidate would expect to receive '0' marks in the test.ardz24 wrote:In a multiple-choice test, each question is followed by n options. What is the value of n?
(1) The test is designed in such a way that if a candidate appearing for the test, decides to mark the options for every question in a random manner, the candidate would expect to receive '0' marks in the test.
(2) For every correct answer, a candidate is awarded 1 mark and for every wrong answer, there are −1/3 marks assigned.
What's the best way to determine whether statement 1 is sufficient?
We do not know how many marks are given for the correct answer and how many marks are deducted for the incorrect answer. Insufficient.
(2) For every correct answer, a candidate is awarded 1 mark and for every wrong answer, there are −1/3 marks assigned.
The mark for the correct answer = 1*1/n = 1/n
The negative mark for each incorrect answer = (-1/3)*(n - 1)/n = (1 - n )/3n; for n options, there would be (n - 1) incorrect answers.
Final score = 1/n + (1 - n )/3n; can't get n.
(1) and (2) together
We have 1/n + (1 - n )/3n = 0 => n = 4. Sufficient.
The correct answer: C
Hope this helps!
-Jay
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