急求解！急求解！

faytastic

A company has assigned a distinct 3-digit code number to each of its 330 employees.Each code number was formed from the digits



2, 3, 4, 5, 6, 7, 8, 9



and no digit appears more than once in any one code number.How many unassigned code numbers are there?



A.6

B.58

C.174

D.182

E.399



关于这道题 网友们说是用A（arrangement）来算，我想问问为什么不是用C（combination）来算？

心诚则灵的MM

6个，就是P83-330，肯定用排列，不是组合，因为密码有数字先后顺序。所以是P.