how do you figure out 100P3
100P3 = 100!/(100-3)! = 100*99*98 . This can be done on the calculator here using npr(100,3):
$${\left({\frac{{\mathtt{100}}{!}}{({\mathtt{100}}{\mathtt{\,-\,}}{\mathtt{3}}){!}}}\right)} = {\mathtt{970\,200}}$$
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