**Answer:**

72.1 m

**Explanation:**

Hello!

When the walker walks west, each block he walks will be of 100 m, so the walker walked **4*100m = 400 m **west.

Similarly, when the walker walks south, he walks 20 meters per block, therefore, the walker walked **4*20 m = 80 m **south.

Since the directions west and south are perpendicular, the distance between the start ad end point is:

**d = √(400^2 + 80^2) m = 407.92 m**

However the walker traveled **480 m**

Therefore, the walker traveled **480 - 407.9 m = 72.1 m **farther than the actual distance