How many different batting orders are possible if 9 people are chosen from a group of 12 on a baseball team?

Question

kirbykirby · Answer

$$ 12P9=\frac{12!}{(12-9)!}$$

kirbykirby · Answer

It's a permutation

anonymous · Answer

Could you run me through the equation? THis is a pre test and i haven't seen this before.

kirbykirby · Answer

$12!=12\cdot 11\cdot 10 \cdot 9 \cdot 8 \cdot 7 \cdot 6 \cdot 5 \cdot 4 \cdot 3 \cdot 2 \cdot 1$

anonymous · Answer

So i multiply all that, And i get 479001600 then i set it equal to $$\left(\begin{matrix}479001600 \(12-9)\end{matrix}\right)$$ ?

kirbykirby · Answer

in the denominator (12-9)! = (3)! = 3!

anonymous · Answer

Then i get a number that is 159667200

kirbykirby · Answer

hm, did you do 3! = 3 * 2 * 1

kirbykirby · Answer

the $\large !$ is very important

kirbykirby · Answer

4! = 4 * 3 * 2 * 1
7! = 7*6*5*4*3*2*1
3! = 3*2*1 
etc...

anonymous · Answer

Oh right, Ok so i get 79833600 and i believe that is the answer?

kirbykirby · Answer

yes =]

anonymous · Answer

Thank you so much, That really cleared up a lot

kirbykirby · Answer

your welcome