Q1:
A test has 50 questions. A student scores 1 mark for a correct answer, -1/3 for a wrong
answer, and -1/6 for not attempting a question. If the net score of a student is 32, the number
of questions answered wrongly by that student cannot be less than
1. 6 2. 12 3. 3 4. 9
pl explain . thanks.
Oa- [spoiler].....3) 3.[/spoiler]
scores..
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Say, the number of correct answers = x, number of wrong answers = y and number of questions not attempted = z.anjaneiya wrote:Q1:
A test has 50 questions. A student scores 1 mark for a correct answer, -1/3 for a wrong
answer, and -1/6 for not attempting a question. If the net score of a student is 32, the number
of questions answered wrongly by that student cannot be less than
1. 6 2. 12 3. 3 4. 9
pl explain . thanks.
Thus, (x + y + z) = 50 and (x - y/3 - z/6) = 32
The second equation can be written as, (6x - 2y - z = 192)
Adding the two equations we get, (7x - y) = 242 => x = (242 + y)/7
Since, x and y are both integers, (242 + y) must be divisible by 7 for integer values of y.
The minimum value that y can have is 3.
The correct answer is C.
Rahul Lakhani
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Quant Expert
Gurome, Inc.
https://www.GuroMe.com
On MBA sabbatical (at ISB) for 2011-12 - will stay active as time permits
1-800-566-4043 (USA)
+91-99201 32411 (India)