Question

the distance between two station A and B is 540km. two trains start simultaneously from these stations on parallel tracks to cross each other . the speed of one of them is greater than the other by 5 km/h. if the distance between these two trains after 3 hours of their start is 165 km, find the speed of each train .​​

Answer 1

Answer:

Let r be the speed of first train.

And r+5 be the speed of other train.

The distance first train travels in 2 hours is =2r

The distance other train travels in 2 hours is (r+5)×2=2(r+5)

Now we know that the distance the first train travels (2r) plus the distance the other train travels 2(r+5) equals 340−30=310.

So, 2r+2(r+5)=310

⇒2r+2r+10=310

⇒4r=300

⇒r=75

Thus, speed of first train is 75 mph.

Therefore, the speed of other train is r+5=75+5=80 mph.

Answer 2

Distance travelled = 540 - 165 = 375 km

Speed: Let speed of one train be x km/h. Then speed of other will be (x + 5) km /h

Speed = 2x + 5 km/h

Time = 3 hours

Speed = Distance/Time

→ 2x + 5 = 375/3

→ 2x + 5 = 125

→ 2x = 120

→ x = 60 km/h

Speed of trains = 60 km/h, 65 km/h