A train travels at a certain average speed for a distance of \(45 \ km\) and then travels a distance of \(54 \ km\) at an average speed of \(6 \ km/h\) more than its original speed. If it takes \(3\) hours to complete the total journey, compute its original average speed?
 
Answer:
 
The original average speed of the train is \(km/h\).