9个数字选3个有多少种组合方式

简介：Because there are rumors in the capital that the autumn examination next year, that is, the provincial examination, will include three new subjects in addition to the study of saints. Although I don’t know which three subjects will be mathematics, physics, geography, and geometry? But no matter which three subjects it is, it will have a huge impact on the autumn examination and the imperial examination of the Ming Dynasty.