d/D=3/(n-3) d=3/(5-3)*2.5=3.75(mm)
中斷時(shí)間=終止時(shí)間-起始時(shí)間=1-9=5(小時(shí)) 故障時(shí)間=中斷時(shí)間-單程乘車(chē)時(shí)間=5-70/35=3(小時(shí))