SOLUTION: Four workers are building a house. In five days they built half the house. But winter is coming and they want to finish building the house in two more days. How many friends shou

Click here to see ALL problems on Average

Question 1152573: Four workers are building a house. In five days they built half the house. But
winter is coming and they want to finish building the house in two more days.
How many friends should the workers call for help, if they do not want to bother
more people than is necessary?
Found 3 solutions by ankor@dixie-net.com, greenestamps, josgarithmetic:
Answer by ankor@dixie-net.com(22740)   (Show Source):
You can put this solution on YOUR website!
Four workers are building a house.
In five days they built half the house.
But winter is coming and they want to finish building the house in two more days.
How many friends should the workers call for help, if they do not want to bother
more people than is necessary?
:
Find how many man-days to complete a house
2(4*5) = 40 man-days
:
let m = no. of additional men required to complete in 2 days
(20 man-days to complete 1st half the house)
20 + 2(m+4) = 40
2m + 8 = 40 - 20
2m = 20 - 8
2m = 12
m = 6 more men required

Answer by greenestamps(13200)   (Show Source):
You can put this solution on YOUR website!

There are of course many different ways to solve the problem. The solution from the other tutor uses formal mathematics, which is fine.

I prefer a less formal solution using common sense, like this:

Half the house was built by 4 workers in 5 days. So 20 man-days builds half of a house.

The other half remains to be built; it will require another 20 man-days.

They want to finish in 2 days; the number of workers required is 20/2 = 10.

There are currently 4 workers; the number of additional workers required is 10-4=6.

Answer by josgarithmetic(39617)   (Show Source):
You can put this solution on YOUR website!
r, the rate for one worker
n, the number of extra friends to help

-------------------------------------------------------------------
Four workers are building a house. In five days they built half the house. But
winter is coming and they want to finish building the house in two more days.
How many friends should the workers call for help?
------------------------------------------------------------------

AND