Question

The distance between two stations is $340km$. 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 $5km/hr$. If the distance between the two trains after $2$ hours of their start is $30km$, find the speed of each train.

Answer 1

let the speed of first train is $xkm/h$

Then the speed of another train is $(x+5)km/h$

Since, Distance $=$ Speed $\times$ Time

Distance travelled by first train in two hour $=x\times 2=2x$

Distance travelled by another train $=(x+5)\times 2=2x+10$

The total distance travelled by two trains $=2x+2x+10=4x+10$ ---(1)

Since, the distance between the two trains after $2$ hours is $30km$.

The distance between two stations is $340km$

$\Rightarrow$ Total distance travelled by two trains $=340km-30km=310km$. ---(2)

From (1) and (2)

$4x+10=310$

$\Rightarrow 4x=310-10=300$

$\Rightarrow x=\frac{300}{4}$

Therefore, the speed of the first train $=75km/h$

Speed of another train $=75+5=80km/h$