Question

甲乙丙三人赛跑,同时从起点出发后甲比乙早10分到达终点,乙比丙早10分到达终点,已

Answer 1

设路程为s,丙用时t,丙速度v,列方程式

s=vt=(v+5)(t-20)=(v+2)(t-10)

vt=vt-20v+5t-100 20v=5t-100

vt=vt-10v+2t-20 10v=2t-20 20v=4t-40

5t-100=4t-40 t=60

v=10

s=vt=600