A car travels 100 km at a speed of 60 km/h and returns with a speed of 40 km/h. Calculate the average speed for the whole journey.

Explanation

To solve the problem of calculating the average speed for the whole journey of the car, we can follow these steps:

### Step 1: Calculate the Total Distance
The car travels 100 km to the destination and then returns 100 km back. Therefore, the total distance (D_total) is:
\[ D_{total} = 100 \text{ km} + 100 \text{ km} = 200 \text{ km} \]

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