Inspired by Morozkin's problem :
Two children started at 6:00 and each walked at a constant (different) speed.
A boy went from A to B and a girl from B to A. They met at noon and continued with no stops. The boy arrived at B at 4 p.m.
At what time did the girl arrive at A?
10 p.m.6 p.m.8 p.m.9 p.m.