SOLUTION: mr. meyers is creating a seating chart for his class. There are 12 desks for 9 students. If he creates a different seating chart for every day, how many days will pass until he has

Algebra ->  Probability-and-statistics -> SOLUTION: mr. meyers is creating a seating chart for his class. There are 12 desks for 9 students. If he creates a different seating chart for every day, how many days will pass until he has      Log On


   



Question 1052727: mr. meyers is creating a seating chart for his class. There are 12 desks for 9 students. If he creates a different seating chart for every day, how many days will pass until he has to repeat a seating chart?
Answer by KMST(5328) About Me  (Show Source):
You can put this solution on YOUR website!
He can assign
Adam to any of the 12 desks.
In each of those cases, th first choice leaves 12-1=11 choices of seat for Bob.
For each of the 12%2A11 resulting cases, there would be 10 choices for the seat assigned to Carl.
For each of the 12%2A11%2A10 sets of seats assigned to Adam, Bob, and Carl, there would be 9 possible places to sit Daniel.
So far we have 12%2A11%2A10%2A9 ways to sit the first 4 students,
and Mr Meyers still has to choose seats for Ed, Frank, George, Harry, and Ian.
All in all, he has 12%2A11%2A10%2A9%2A8%2A7%2A6%2A5%2A4=79833600 possible seating arrangements.
To go through all 79.8336 million possible seating charts would take him that many days. assuming the class meets for 365 days per year, that would be over 200 thousand years. I do not believe Mr Meyers can live that long.