Question 1093214
<br>Another nice algebraic solution from Boreal...<br>
But let's see if a more informal solution makes sense to you.<br>
The stations are 306km apart; one train travels twice as fast as the other.  That means that, at the time the trains pass each other, the faster train has covered 2/3 of the distance and the slower train has covered 1/3 of the distance.<br>
2/3 of the 306km for the faster train is 204km; since both trains traveled for 3 hours before they passed each other, the speed of the faster train is 204/3 = 68km/hr. And then the speed of the slower train is half of that, or 34km/hr.