So hoc sinh gai la: 19+2=21 (hocsinh)
Tong so hoc sinh ca lop la: 19+21=40(hoc sinh)
So phan tram hoc sinh trai la: \(\frac{19}{40}\times100\%=47,5\%\)
So phan tram hoc sing gai la: \(\frac{21}{40}\times100\%=52,5\%\)
So hoc sinh gai la: 19+2=21 (hocsinh)
Tong so hoc sinh ca lop la: 19+21=40(hoc sinh)
So phan tram hoc sinh trai la:
19 : 40 x 100 = 47.5%
So phan tram hoc sing gai la:
21 : 40 x 100 = 52.5%