The speed of the slower train is 75 km/h, calculated by solving the equation derived from the time difference between the two trains covering 150 km.
To solve this problem, let's assume the speed of the faster train is x km/h. Since the difference in the average speed of the two trains takes 2 hours longer than the faster train takes to travel 150 km, we can set up the equation:
Time taken by the slower train to travel 150 km = Time taken by the faster train to travel 150 km + 2 hours
This can be expressed as:
150/x = 150/x + 2
Now, we can solve this equation to find the speed of the slower train:
150/x - 150/x = 2
150/x = 2
x = 150/2
x = 75
Therefore, the speed of the slower train is 75 km/h.