Answer :
The trains will take 25 minutes to be 50km apart from eachother.
After 5 mins the trains are 10km & in 15 mins they are 30km.
So 5minsx5=25mins and 10kmx5=50km
The trains will take 25 minutes to be 50km apart from eachother.
After 5 mins the trains are 10km & in 15 mins they are 30km.
So 5minsx5=25mins and 10kmx5=50km