SOLUTION: Betty paints twice as fast as dan. Working together, dan and betty can paint 2400 sq. ft. in 4 hours. Another employee sue joined their painting team. Working together dan betty an

Algebra ->  Rate-of-work-word-problems -> SOLUTION: Betty paints twice as fast as dan. Working together, dan and betty can paint 2400 sq. ft. in 4 hours. Another employee sue joined their painting team. Working together dan betty an      Log On


   

Question 666040: Betty paints twice as fast as dan. Working together, dan and betty can paint 2400 sq. ft. in 4 hours. Another employee sue joined their painting team. Working together dan betty and sue can paint 3600 sq. ft. in 3 hours
If sue works alone how many sq ft can she paint in 4 hours and 27 minutes

Answer by vleith(2983) About Me  (Show Source):
You can put this solution on YOUR website!
dan and betty can paint 2400sq ft in 4 hours. So that is 2400/4 = 600 sq ft per hour.
Betty can paint twice as much as dan, so {d + 2d = 600}}}
d=600%2F3+=+200
Dan can do 200 sq ft/hour. Bety can do twice that, 400sq ft/hour
Now you are told they get sue to help.
The three of them paint 3600 sq ft in 3 hours.
You know dan and Betty do 600 sq ft/hour. So the two of them will do 1800 sq ft in 3 hours. That mean sue does 3600+-+1800+=+1800 sq ft in 3 hours.
So sue does 600 sq ft /hour
Use that rate to see how much sue can paint in 4 hours 27 minutes (remember that 27 minutes is 27/60 of an hour