Question 125848
For each trip, {{{d = r*t}}} in km. For both trips the distance is the 
same. The time spent each trip will be different 
For campsite to ranch:
{{{d = 5.2*t[1]}}}
For ranch to campsite:
{{{d = 7.8*t[2]}}}
{{{5.2*t[1] = 7.8*t[2]}}}
Also given is
{{{t[1] + t[2] = 3.5}}} hrs
{{{t[2] = 3.5 - t[1]}}} hrs
{{{5.2*t[1] = 7.8*t[2]}}}
{{{5.2*t[1] = 7.8(3.5 - t[1])}}}
{{{5.2*t[1] = 27.3 - 7.8*t[1]}}}
{{{13*t[1] = 27.3}}}
{{{t[1] = 2.1}}} hrs
Plug this back into 1st equation
{{{d = 5.2*t[1]}}}
{{{d = 5.2*2.1}}}
{{{d = 10.92}}} km answer
check the other equation:
{{{t[2] = 3.5 - t[1]}}}
{{{t[2] = 3.5 - 2.1}}}
{{{t[2] = 1.4}}}
{{{d = 7.8*t[2]}}}
{{{d = 7.8*1.4}}}
{{{d = 10.92}}}
OK