A car completes a journey in 10 minutes. For the first of the distance the speed was 60 km/h and for the second half the speed was 40 km/h. how far is the journey?

Answer 1

Let the total distance be x.
(x/2)/60 + (x/2)/40 = (10minutes)/(60minutes/hour)
x/120+x/80 = 1/6
multiply by common denominator 240
2x+3x = 40
5x=40
x=8 km