发布时间:2019-08-10 18:00:24
得优的=40*0.2+30*0.1=11人,一共40+30=70人,得优百分比=11/70=15.7%
(40*20% + 30*10%)/(40+30) *100% = 11/70 *100% = 15.7%
请采纳
(40*20%+30*10%)/(40+30)
=(8+3)/70
=11/70
=15.7%