[tex]6\dfrac{2}{3}=\dfrac{6\cdot3+2}{3}=\dfrac{20}{3}\\\\v=\dfrac{s}{t}\\\\v=57mph;\ t=\dfrac{20}{3}h;\ s=?[/tex]
substitute
[tex]\dfrac{s}{\frac{20}{3}}=57\ \ \ |\cdot\dfrac{20}{3}\\\\s=57\cdot\dfrac{20}{3}\\\\s=19\cdot20\\\\s=380\ miles[/tex]
Answer: 380miles.