Question 848897
s=2d
s+d=3d
3d=2400 in 4 hours
d=800 in 4 hrs 200 in 1 hr
s=1600 in 4 hrs 400 in one hour

3*200+3*400=600+1200=1800 for s and d in 3 hours
which means that Roger and Sue can  do 1800 sq ft in 3 hours.
We don't have enough info to know how Roger works alone.


If you meant roger and sue alone then ask again.