Question

[Cô bé thần nông]

ket qua xep loai hoc luc cua lp 6c gom :gioi kha tb.So h/skha la 20 em,so h/s gioi chiem 3/5 so h/s kha.So h/s tb =50% tong so h/s kha &gioi

a,tinh so h/s cua lop 6c

b,tinh ty so % cua so h/s gioi voi so h/s ca lop.

thanks very much