Question

The distance between two stations is 425 km. two train start simultaneously for the stations on parallel tracks to cross each other, the speed of one of them is greater than the other by 5 kilometres per hour if the distance between two trains after 3 hours of the start is 20 km. find the speed of each train

Answer 1

Let the trains be A and B.
Speed of A = x km/h
Speed of B = (x+5) km/h

After 3 hours,
distance travelled by A = 3x km
distance travelled by B = 3(x+5) km
= 3x+15 km

Now distance between them is 20km
So 3x + (3x+15) + 20 = 425
6x + 35 = 425
6x = 425 – 35 = 390
x = 390/6
= 65 km/h
x + 5 = 65+5
= 70 km/h

Speed of the trains are 65 km/h and 70 km/h.

Hope it helps
All the best.