Question 1023824
{{{d}}}= distance walked (one way), in km
{{{d/10}}}= time (in hours) spent going at {{{10}}}{{{"km / h"}}}
{{{d/8}}}= time (in hours) spent returning at {{{8}}}{{{"km / h"}}}
{{{4d/40+5d/40=9}}}
{{{9d/40=9}}}
{{{(9/40)*d=9}}}
{{{(40/9)*(9/40)*d=(40/9)*9}}}
{{{highlight(d=40)}}}
Shirley walked 40 km each way.