Question

甲乙两人跑步,相向而行,a小时相遇,反向而行,甲追上乙b小时,问甲速度是乙的多少倍?

Answer 1

(a+b)/(b-a)倍

设甲速度V1,乙速度V2,总路程S,S/(V1+V2)=a,S/(V1-V2)=b

S/a=V1+V2

S/b=V1-V2

故V1=(S/a+S/b)/2=S*(a+b)/2ab

V2=(S/a-S/b)/2=S*(b-a)/2ab

两式相除得出答案.