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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?

 Sep 15, 2017
 #1
avatar+128475 
+2

 

The test must contain at least 5 questions

 

To see why....4 questions can only be arranged  in 4!  =  4 * 3  * 2 * 1  = 24 different ways.......and this will not be enough.....no matter how she arranges the questions, some students will share the same arrangement

 

5 questions can be arranged  in 5!  = 5 * 4 * 3 * 2 * 1    = 120 different ways......and this will be more than enough

 

 

 

cool cool cool

 Sep 15, 2017

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