SOLUTION: IF IT TAKES SALLY 4 HOURS TO PAINT A HOUSE AND IT TAKES JOHN 6 HOURS TO PAINT THE SAME HOUSE, HOW LONG WOULD IT TAKE THEM TO PAINT THE SAME HOUSE TOGETHER. ANSWER: 2 HOURS AND 2

Algebra ->  Equations -> SOLUTION: IF IT TAKES SALLY 4 HOURS TO PAINT A HOUSE AND IT TAKES JOHN 6 HOURS TO PAINT THE SAME HOUSE, HOW LONG WOULD IT TAKE THEM TO PAINT THE SAME HOUSE TOGETHER. ANSWER: 2 HOURS AND 2      Log On


   

Question 75458: IF IT TAKES SALLY 4 HOURS TO PAINT A HOUSE AND IT TAKES JOHN 6 HOURS TO PAINT THE SAME HOUSE, HOW LONG WOULD IT TAKE THEM TO PAINT THE SAME HOUSE TOGETHER.
ANSWER: 2 HOURS AND 24 MINUTES
Answer by funmath(2933) About Me  (Show Source):
You can put this solution on YOUR website!
If Susie can paint a house in 4 hrs and John can paint a house in 6 hrs. How long will it take them to paint it together?
This is the way I was taught this, but I know there is another way to do this:
Susie can paint 1 house in 4 hrs, her work rate is:1/4
John can paint 1 house in 6 hrs, his work rate is: 1/6
They both can paint 1 house in x hrs, their combined work rate is:1/x
:
Problem to solve:
1%2F4%2B1%2F6=1%2Fx
%283%2F3%29%281%2F4%29%2B%282%2F2%29%281%2F6%29=1%2Fx
3%2F12%2B2%2F12=1%2Fx
5%2F12=1%2Fx Cross multiply, or flip both sides over and you have:
5x=12
5x%2F5=12%2F5
x=12%2F5
x=12/5 hrs.
x=2 and 2/5 hrs there are 60 minutes in an hour
x=2 hrs and (2/5)(60)min
x=2 hrs and 24 mins.
Happy Calculating!!!!