fast train takes 3hrs less than slow train for 600km speed of slow train10km/hr less than fast trai

Let speed of fast train be x.

Speed of slow train= x-10.

As per question:

600/x = 600/(x-10)  -3

600(1/(x -10)- 1/x)=3

x(x-10)=2000

x²-10x-2000=0

Hence x=50

Speeds of train are 50 km/h and 40 km/h.