Question 1159414
The round-trip is  216 miles.


The trip's cost:  {{{216*miles*(1/8.7)(dollars/miles)=theCostInDollars}}}


Robertas and her friends, makes 5 people to share this  {{{216/8.7)}}} dollars of cost.  Just multiply by  {{{1/5}}} to get the contribution of each friend.