SOLUTION: If my friend has to paint a room for 1 hour . And if i have to paint the same size of room it will take 2 hours . How long we have to paint the room if we are to paint it toget

Algebra ->  Rate-of-work-word-problems -> SOLUTION: If my friend has to paint a room for 1 hour . And if i have to paint the same size of room it will take 2 hours . How long we have to paint the room if we are to paint it toget      Log On


   

Question 962234: If my friend has to paint a room for 1 hour .
And if i have to paint the same size of room
it will take 2 hours . How long we have to
paint the room if we are to paint it
together?
Found 2 solutions by josgarithmetic, lwsshak3:
Answer by josgarithmetic(39631) About Me  (Show Source):
You can put this solution on YOUR website!
Your rate when both of you work together is additive.

%281%2F1%2B1%2F2%29=2%2F2%2B1%2F2=3%2F2

That is 3 rooms in 2 hours,
or
1 room in 2/3 hours.

Answer by lwsshak3(11628) About Me  (Show Source):
You can put this solution on YOUR website!
If my friend has to paint a room for 1 hour .
And if i have to paint the same size of room
it will take 2 hours . How long we have to
paint the room if we are to paint it
together?
***
my friend has to paint a room for 1 hour
his work rate=1/1=1
I can paint a room in 2 hours
my work rate=1/2
together we can paint the room in x hours
our work rate=1/x
..
sum of indv. work rates= work rate working together
1+1/2=1/x
3/2=1/x
x=2/3
How long we have to
paint the room if we are to paint it
together? 2/3 hr or 40 min