A car travelled the first third of a distance (x) at a speed of `10 km//h`, the second third at a speed of ` 20 km//h` and the last third at a speed of ` 60 km//h`. Determine the average speed of the car over the entire distance (x).

Explanation

To find the average speed of the car over the entire distance \( x \), we can follow these steps:

### Step 1: Define the distance segments
The total distance \( x \) is divided into three equal parts:
- First third: \( \frac{x}{3} \)
- Second third: \( \frac{x}{3} \)
- Last third: \( \frac{x}{3} \)

...