Question 9
A, B and C are the homes of An, Binh and Chau, collinear in that order; T is their school. AT=6 km, AB=4 km and BC=5 km. Binh leaves at 6:00 and reaches school at 7:00. If Chau also leaves at 6:00 and all walk at the same speed, when does Chau arrive?
