To find out how many miles Kelly walks after three days, you can multiply the distance she walks each day by the number of days.
Kelly walks \( \frac{4}{5} \) of a mile each day, and she walks for 3 days.
So, the total distance she walks in three days is:
\[ \text{Total distance} = \left( \frac{4}{5} \text{ miles/day} \right) \times 3 \text{ days} = \frac{4 \times 3}{5} = \frac{12}{5} \text{ miles} \]
Now, we can simplify \( \frac{12}{5} \):
\[ \frac{12}{5} = 2 \frac{2}{5} \text{ miles} \]
Thus, Kelly walks \( \frac{12}{5} \) miles, or \( 2 \frac{2}{5} \) miles, after three days.