exercise:A13caea835: Difference between revisions
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A multiple choice exam is given. A problem has four possible answers, and exactly one answer is correct. The student is allowed to | |||
possible answers, and exactly one answer is correct. The student is allowed to | |||
choose a subset of the four possible answers as his answer. If his chosen subset | choose a subset of the four possible answers as his answer. If his chosen subset | ||
contains the correct answer, the student receives three points, but he loses one | contains the correct answer, the student receives three points, but he loses one | ||
point for each wrong answer in his chosen subset. Show that if he just guesses a | point for each wrong answer in his chosen subset. Show that if he just guesses a | ||
subset uniformly and randomly his expected score is zero. | subset uniformly and randomly his expected score is zero. | ||
Latest revision as of 16:32, 14 June 2024
A multiple choice exam is given. A problem has four possible answers, and exactly one answer is correct. The student is allowed to choose a subset of the four possible answers as his answer. If his chosen subset contains the correct answer, the student receives three points, but he loses one point for each wrong answer in his chosen subset. Show that if he just guesses a subset uniformly and randomly his expected score is zero.