如果448是千米:
(1)448/(60+80)=448/140=3.2小时,过3.2小时相遇.
(2)(448-60*28/60)/(60+80)=420/140=3小时,快车开出后3小时两车相遇
(3)448/(80-60)=448/20=22.4小时,22.4小时快车追上慢车.
如果448是千米:
(1)448/(60+80)=448/140=3.2小时,过3.2小时相遇.
(2)(448-60*28/60)/(60+80)=420/140=3小时,快车开出后3小时两车相遇
(3)448/(80-60)=448/20=22.4小时,22.4小时快车追上慢车.