SOLUTION: Eva can wallpaper a room in 4 hours and Kathy can wallpaper the same room in 6 hours. Kathy works on her own for one hour, and is then joined bye Eva. Assuming these rates, how man

Algebra ->  Rate-of-work-word-problems -> SOLUTION: Eva can wallpaper a room in 4 hours and Kathy can wallpaper the same room in 6 hours. Kathy works on her own for one hour, and is then joined bye Eva. Assuming these rates, how man      Log On


   



Question 208993: Eva can wallpaper a room in 4 hours and Kathy can wallpaper the same room in 6 hours. Kathy works on her own for one hour, and is then joined bye Eva. Assuming these rates, how many hours did Kathy and Eva together take to finish the job?
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
Eva can wallpaper a room in 4 hours and Kathy can wallpaper the same room in 6 hours.
Kathy works on her own for one hour, and is then joined bye Eva.
Assuming these rates, how many hours did Kathy and Eva together take to finish the job?
:
Let t = time required when they work together
:
Let the completed job = 1
:
Each will do a fraction of the job. the two fractions add up to 1
t%2F4 + t%2F6 = 1
Multiply equation by 12
12*t%2F4 + 12*t%2F6 = 12*1
Cancel denominators
3t + 2t = 12
:
5t = 12
t = 12%2F5
t = 2.4 hrs working together
;
;
Check solution:
2.4%2F4 + 2.4%2F6 =
.6 + .4 = 1