Question

a fast train takes 3 hours less than a slow train for journey of 600 km. if speed of the slow train is 10 km per hour less than fast train. find speed of both the trains.

Answer 1

Slow train speed be x and fast be y
y-x = 10 km/hr (given)
Time difference is 3 hours

t2 = t1+3
For journey of 600 Kms, fast train takes 3 hours less time
Distance d= 600
d= speed * time
for fast train d = y*(t1+3)
slow train d= x*(t1)

600= yt1 +3y
600= xt1
By combination of the speeds , trial and error as the difference is given.

12 and 15 hours journey is an ideal case
Fast train takes 12 hours to cover 600kms with speed 50km/hr

And slow train takes 15 hours to cover 600kms with speed 40km/hr