12 minutes
1) Gathering the data
4/5 miles away
4 miles per hour
2) Drawing the scenario:
Since they walk at a steady pace of 4 mph let's call this Velocity as the Average Velocity which can be calculated using this
[tex]\begin{gathered} V=\frac{\Delta S}{\Delta t} \\ \frac{4}{60}=\frac{\frac{4}{5}}{\Delta t} \\ \frac{1}{15}=\frac{\frac{4}{5}}{\Delta t} \\ \Delta t\text{ =15 }\cdot\frac{4}{5} \\ \Delta t\text{ = 12} \end{gathered}[/tex]To Convert miles per hour to miles per minute, let's divide it by 60
1 hour = 60'. And then simplify this:
So it'll take 12 minutes.
