SOLUTION: Tina can paint a fence in 8 hours. Tom can paint the same fence in 4 hours. How long will it take them to paint the fence if they work together?

Algebra ->  Rate-of-work-word-problems -> SOLUTION: Tina can paint a fence in 8 hours. Tom can paint the same fence in 4 hours. How long will it take them to paint the fence if they work together?      Log On


   

Question 754822: Tina can paint a fence in 8 hours. Tom can paint the same fence in 4 hours. How long will it take them to paint the fence if they work together?
Found 2 solutions by sachi, Cromlix:
Answer by sachi(548) About Me  (Show Source):
You can put this solution on YOUR website!
Tina can paint a fence in 8 hours.
so Tina can paint 1/8 parts in 1 hr
Tom can paint the same fence in 4 hours.
so Tom can paint 1/4 parts in 1 hr
so both can paint 1/8+1/4=3/8 parts in 1 hr
so the total time taken by both to paint the fence=8/3hrs

Answer by Cromlix(4381) About Me  (Show Source):
You can put this solution on YOUR website!
Tina's rate = 1/8 job/hr
Tom's rate = 1/4 job/hr
Together the rate is 1/x job/hr
Equation: rate + rate = together rate
1/8 + 1/4 = 1/x
Common denominator = 8x
x + 2x = 8
3x = 8
x = 8/3 or 2 2/3 hrs
Therefore they can do the job together in
2 hours 40 minutes.
Hope this helps
:-)