Question

Lonavala and khandala are two stations 600 km apart. a train starts from lonavala and moves towards khandala at the rate of 25 km/h. after two hours, another train starts from khandala at the rate of 35 km/h. how far from lonavala will they will cross each other?

Answer 1

Hello Dear.

Here is the answer---

Distance between the Two Stations = 600 km.

In First Case, (Train From Lonavala)

Speed = 25 km/hr.
In first two hours, only train from Lonavala Travels,
∴ Time = 2 hrs.

∵ Distance = Speed × Time.
 ∴ Distance = 25 × 2
    Distance = 50 km.

∴ Distance covered by the Train after starting from the Lonavala before the  train from Khandala starts = 50 km.


Now, Train from the khandala also starts, thus distance between the two train = 600 - 50
= 550 km.

Relative speed = Speed of train which starts from Lonavala + Speed of the train which starts from the khandala 
= 25 + 35
= 60 km/hr.

Now, Time at which these two trains meet after travelling = Distance between these Train/Relative Speed
= 550/60
= 55/6 hrs.

Now, In 55/6 hrs, Distance covered by the First Train after the train from the khandala starts = (55/6) × 25
= 1375/6 km.
= 229.167 km.

∴ Distance at which the Both train meets from Lonavala = Distance travelled by train from Lonavala in first two hours + Distance travelled by it after the another train from the khandala starts.
= 229.167 + 50
= 279.167 km.


∴ Both the trains meet after at the distance of 279.167 km from the Lonavala. 


Hope it helps.

Answer 2

Answer:

Explanation:

When the train from Khandala starts off, the train from Lonavala will already have covered 50 kms.

Hence, 550 km at a relative speed of 60 kmph will take 550/60 hrs.

From this, you can get

the answer as: 50 + (550/60) * 25 = 279.166 km

hope this helps