數學問題?

設從油站往機場的距離為s,

則根據題意:

貨車從油站駛往機場,開了一小時後,所用時間與私家車從該油站沿相同的路徑前往機場的時間相 等,

已知:
T(時間)=S(距離) / V(速率)
代入:
(S-(1*50))/50=S/70
解題: 70S-3500=50S
20S=3500
S=175(km)

該段的長度為175公里

Speed = Distance / Time
Distance = Speed* Time

D(lorry) = Speed * Time
= 50 *T

D(car) = Speed*Time
= 70* (T-1)
[since the car started one hour after the lorry had set off, the car took one hour less to cover the same distance]

D(lorry) =D(car) [the same, drove the same path]
50*T =70*(T-1)
50T=70T-70
70=20T
T=3.5hours

hope it's correct.

2007-04-02 22:47:42 補充：
Distance = 50*3.5 =175 km