Question 379740: One car travels 40 km/hr faster than another. While one travels 150 km, the other goes 350 km. Find the speed of the slower car Found 2 solutions by ewatrrr, fractalier:Answer by ewatrrr(24785) (Show Source):
Hi,
Let x represent speed of slower car and (x +40mph) the speed of the faster
D = r*t OR D/r = t Times being the same, sets up the equality:
cross multiplying to solve for x
350x = 150(x + 40)
350x = 150x + 40*150
200x = 40*150
x = 40*150/200 = 6000/200
x =30kmph, the speed of slower car
You can put this solution on YOUR website! The working equation is always distance = rate x time, or d = rt.
If the cars travel for the same time t, and we call the speed of the slower car r, the faster car travels at a speed of r+40.
So
150=rt
350=(r+40)t
Let us solve the first one for t and substitute it into the second, thus solving for r, the speed of the slower car. So...
t = 150/r
and km/hr
