Question 50777
Let the speed on the country road be 3x
x = mountain speed
50 miles were driven on mountain road
EQUATION:
{{{150/3x+50/x=5}}}
{{{150x+50(3x)=5((3x)(x))}}}
{{{300x=15x^2}}}
{{{x^2-20x=0}}}
x=0 or x=20
20(3)=60
Hence, the speed on the country road was 60mph.
Paul.