Question

2 trains start simultaneously from 2 stations 300 km apart and move towards each other. The speed of one train is more than the other by 20 km/h. If the distance b/w the trains after 2 hours is 20 km, find the speed of trains

Answer 1

solution:

Let the train be a and b speed of a = x km/h

Speed of b = (x+20)km/h

After the 2 hours

Distance travelled by A =  2x

Distance travelled by B= 2(x +20)km/h

=2x +40

Now distance between them is 20km  

So,

2x +(2x+40)+20=300

4x +60=300

4x = 240

X=60km/h

X+20=60+20=80km/h

Speed of train are 60km/h and 80km/h

Answer 2

Let the trains start from station A and station B respectively.

Let the first train start from station A and the second train start from station B at the same time and move towards each other.

Let the speed of the first train be x km/hr

∴ the speed of the second train =(x+20) km/hr

Distance travelled by first train in 2 hours =2x km

Distance travelled by second train in 2 hours =2(x+20) km =(2x+40) km

Given, distance between two stations =300 km

According to the given condition, we have

Distance travelled by first train + Distance travelled by second train +20=300

i.e., 2x+(2x+40)+20=300

4x+60=300

4x=300−60 ....[Transposing 60 to RHS]

4x=240

Thus, x= 4/240

=60

∴ Speed of the first train =60 km/hr speed of the second train =(60+20) krn/h =80 km/hr.

By Aastha