Question 918959
 {{{45/r -60(r+11) = 2}}}
2r^2 + 37r - 495 = 0 (Tossing out the negative solution for unit measure)
r = {{{x = (-37 +- sqrt( 5329))/(4) }}} 
r = {{{x = (-37 +- 73)/(4) }}} 
r = 9mph, Doreen'x speed.  Her time 5hr
Sue 20mph.  Her time 3hr