Question

[nguyen thi phuong hang]

mot o to va mot xe may cung xuat phat luc 7gio 30phut de di tu AdenB .Van toc cua xe may bang3/4 van toc cua o to .Hoi xe may den B luc may gio, biet quang duongAB dai 120km va o to den B luc 10 gio