SOLUTION: 7P(n,3) = 6P(n+1,3) Not sure why the answer is n=20.

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Question 117274: 7P(n,3) = 6P(n+1,3)
Not sure why the answer is n=20.
Answer by Edwin McCravy(20054)   (Show Source): You can put this solution on YOUR website!



 = 

Not sure why the answer is n=20.

----------------------------------

Use the identity  = 
to rewrite the permutations on both sides:

 = 

 = 

Multiply both sides by 

 = 

On the left, write  as 

 = 

Cancel the 's on the left and the
's on the right:


 = 

 = 

On the right, write  as 

 = 

Divide both sides by 

 = 

 = 

 = 

Edwin
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