SOLUTION: The problem is P(n,2)=42, find n. The instructor gave the answer for n, which is 7. I figured out the formula knowing the answer is 7, which is n!/(n-k)!
I need to know the formul
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Question 147870This question is from textbook Mathematical Excursions
: The problem is P(n,2)=42, find n. The instructor gave the answer for n, which is 7. I figured out the formula knowing the answer is 7, which is n!/(n-k)!
I need to know the formula to figure out how to get the value of n. Thank you.
This question is from textbook Mathematical Excursions
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
P(n,2)=42, find n.
------------
n!/(n-2)! = 42
n(n-1) = 42
n^2 -n - 42 = 0
(n-7)(n+6) = 0
Positive answer:
n = 7
============
Cheers,
Stan H.
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