(10)164-11×11=153(km)153÷(11+14)=6.12(h)6.12+1=7.12(h)(11)设全长为xm,则有相遇时间为x/(48+54)54×x/(48+54)=1/2x+3054×1/102x=1/2x+3027/51x=1/2x+3027/51x-1/2x=301/34x=30x=1020(12)24×50=1200(m)1200÷(200-50)=8(分)
