A train travels at a certain average speed for a distance of 63km and then travels a distance of 72km at an average speed of 6 km/hr more than its original speed. If it takes 3 hours to complete the total journey, what is its original average speed?

Explanation

To solve the problem, we will follow these steps:

### Step 1: Define the Variables
Let the original average speed of the train be \( x \) km/hr.

### Step 2: Express the Speeds
The speed for the second part of the journey is \( x + 6 \) km/hr (6 km/hr more than the original speed).

...