A teacher is making a multiple choice quiz. She wants to give each student the same questions, but have each student's questions appear in a different order. If there are twenty-seven students in the class, what is the least number of questions the quiz must contain?

Question

A teacher is making a multiple choice quiz.  She wants to give each student the same questions, but have each student's questions appear in a different order.  If there are twenty-seven students in the class, what is the least number of questions the quiz must contain?

bibby · Answer

pretend there are only 5 questions.

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there are 5 ways she can give the first one, 4 the second, etc.
5*4*3*2*1 I believe

anonymous · Answer

With one question there's only 1 permutation.

2 = 2 perms 

3 = 3 * 2 * 1 = 6 

4 = 4 * 3 * 2 * 1 = 24 

5 = 120 permutations so would need 5 questions to give 27 students a different order.