Question

A train leaves a station and travels north at a speed of 105105 ​km/h. twotwo hours​ later, a second train leaves on a parallel track and travels north at 135135 ​km/h. how far from the station will they​ meet?

Answer 1

Let x = hours to meet

train one has a 2 hour head start or 210 km head start

210 + 105x = 135x
30x = 210
x = 7 hours to meet