Question 943978
The word, "return" is creating ambiguity.  I will take the meaning, that the harried parent is making a circuit around the triangle.

Using all units as miles, hours, miles per hour,



_____________________rate___________time___________distance
HOUSEtoSTATION_______r-10___________________________1
STATIONtoSCHOOL______r______________________________1
SCHOOLtoHOUSE________r______________________________1
Total______________________________{{{15/60}}}




_____________________rate___________time___________distance
HOUSEtoSTATION_______r-10___________1/(r-10)_________1
STATIONtoSCHOOL______r______________1/r______________1
SCHOOLtoHOUSE________r______________1/r______________1
Total______________________________{{{1/4}}}



The question means, to find r-10.
{{{highlight_green(1/(r-10)+2/r=1/4)}}}, the equation formable from the data table.  Solve for r, and compute r-10.