Question 1052557
{{{D=R*t}}}
For Sue, 
{{{D[S]=30*t}}}
For Jane, 
{{{D[J]=20*(t-3)}}}
where t is measured from when Sue left. 
{{{D=D[S]+D[J]}}}
{{{30t+20(t-3)=490}}}
{{{30t+20t-60=490}}}
{{{50t=550}}}
{{{t=11}}}{{{hr}}}
So then Sue traveled 11 hours and covered 330 miles and Jane traveled 3 hours less or 8 hours and covered 160 miles.