first, 50km/30min = 100km/hr
so, 200 km takes 2 hr
that's 120 min, but maybe they wanted the time in hours.
you are kind of sloppy with the units in your calculations, switching back and forth between minutes and hours.
You are driving on a Canadian freeway to a town that is 200 kilometers from your home. After 30 minutes you pass a freeway exit that you know is 50 kilometers from your home. Assuming that you continue at the same constant speed, how long will it take for the entire trip?
I did:
50km/30min = 120km/h
200*30/ 50 =h
120 =h
but I got 120 mins wrong.
3 answers
thanks oobleck
50km/0.5h = 100 km/h.
T = (200-50)/100 = 1.5 h.
T = (200-50)/100 = 1.5 h.