Question 988327
Benny: 1 attic/8hours=1/8 attic per hour
working together, in 5 hours Benny cleans (5hr)((1/8)/hr)=5/8 of the attic.
So in 5 hours Donna cleans 3/8 of the attic
Donna: (3/8 attic)/(5hrs)=(3/40) attic/hr
For Donna to clean 1 attic: 
(1 attic)/((3/40)attic/hr)=40/3 hours=13.33 hours
.
ANSWER: It would take Donna 13 hours and 20 minutes to clean the attic alone.