假设甲静止,则错车长度为80+60+80=220m
1.相向行驶时v=25+15=40km/h=100/9m/s t=220/(100/9)=19.8s
2.同向行驶时v=25-15=10km/h=25/9m/s t=220/(25/9)=79.2s