Question 808689
Let m = minutes Roger runs.
Let d = distance until Roger and Jeff ran the same distance.


Runner___________speed(mile/minute)_____time__________distance
Jeff_____________1/21____________________m+1___________d=(1/21)(m+1)
Roger____________1/18____________________m_____________d=(1/18)m


{{{(1/21)(m+1)=(1/18)(m)}}}
Solve for m.  With this, find m+1, the time for Jeff to catchup to Roger.  Use m to find the value for the distance, d.