Question 1054412
1.{{{D[1]=R[1]*t[1]=71}}}
2.{{{D[2]=(R[1]-5)*t[2]=25}}}
3.{{{t[1]+t[2]=5}}}
From 1,
{{{t[1]=71/R[1]}}}
From 2,
{{{t[2]=25/(R[1]-5)}}}
Substituting into 3,
{{{71/R[1]+25/(R[1]-5)=5}}}
Solving this graphically, you get two answers,
{{{R[1]=3.416}}} and {{{R[1]=20.784}}}
However since {{{R[1]-5}}} would be negative when {{{R[1]=3.416}}} use the other answer.
{{{R[1]=20.784}}} for the first part of the trip then,
{{{R[1]-5=15.784}}} for the second part of the trip.