Word Problems: Travel: A car travels 300 km in ....

[Tigertigre2000]

A car travels 300 km in the same time that a freight train travels 200 km. The spped of the car is 20 km/h more than the speed of the train. Find the spped of the frieght train.

How would you solve this problem? Which equation would you use?

 

[Denis]

formula: speed = distance divided by time

hint: let t = train speed; then car speed = t+20

If that's not enough, then you need classsroom help.

 

[skeeter]

let r = car's rate of travel
t = amount of time to travel 300 km

rt = 300

let R = train's rate of travel
t = same amount of time as the car to travel 200 km

Rt = 200

so ...

(rt)/(Rt) = 300/200

r/R = 3/2

you are also told r = R + 20

(R+20)/R = 3/2

cross-multiply, solve for R.