Wendy begins sanding a kitchen floor by herself and works for 3 hours. She is then joined by Bruce, and together the two of them finish sanding the floor in 2 hours. If Bruce can sand the floor by himself in 20 hours, how long would it take Wendy to sand the floor by herself?	Choose the correct option:
A) 9/80 hours B) 3/20 hours C) 20/3 hours D) 80/9 hours E) 506/91 hours
Let Wendy finishes sanding the floor alone in W hours while B be the hours for Bruce.   Thus in 1 hour Wendy finishes 1/w of the work while Bruce finishes 1/B of the work.   If wendy works for 3 hours and is then joined by Bruce to finish the work in 2 more hours,   3/W + 2/W+2/B = 1 (1 denotes the total amount of work)   5/W + 2/B =1 and given B =20 hours.   Thus W = 506/91 hours , 506/91 hours is the correct answer.
<result>E</result>
Wendy begins sanding a kitchen floor by herself and works for 3 hours. She is then joined by Bruce, and together the two of them finish sanding the floor in 2 hours. If Bruce can sand the floor by himself in 20 hours, how long would it take Wendy to sand the floor by herself?