Answer :
if you are going at a speed of 20 mph means that you travel 10 miles in one hour, so if you are at 20 min we can made the transformation like this:
[tex]20\frac{\text{mil}}{\text{hr}}\cdot\frac{1}{60}\frac{hr}{\min}=\frac{1}{3}\frac{\text{mil}}{\min }[/tex]So the time take me to arrive there is:
[tex]\begin{gathered} D=\frac{1}{3}\frac{\text{mil}}{\min}\cdot20 \\ D=6,66\text{mil} \end{gathered}[/tex]so it take 1/3 of hour or 20 mins to travel 6.66 mil