Answer: 362,880
note: this is one single number. The comma helps make it more readable
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Step-by-step explanation:
We have 9 positions to fill. The first position has 9 choices, the second has 8 (since we cannot pick the same person twice), then 7, then 6, and so on until we count down to 1. We multiply out all these values mentioned.
9*8*7*6*5*4*3*2*1 = 362,880
The idea of multiplying whole numbers counting down to 1 is a concept known as factorials. Because order matters, the value 362,880 represents the number of permutations possible.