Many homeowners repairs or rebuilt their home either by themselves or with community help. Reconstruction in some areas was aided by relief agencies, like the Red Cross or Red Crescent.
To rebuild the homes will be some problems for example:
- Twenty five villagers can complete a job to rebuild one home in fifty four days. Because it construction is too long. There some idea to complete the job in twenty seven days. And the question is how many villagers must be added so that the job can be completed in twenty seven days?
The problem can be solved by using invers proportions.
To complete the home in fifty four days it requires twenty five villagers.
If the house can complete in twenty seven days, and the numbers of villagers required is k person.
We can draw in table like this
Since the time (number of days) is decreased, the number of villagers must be increased.
Thus, the above problem is related to inverse proportions.
So, additional of villagers is fifty minus twenty five equals twenty five.
- The problem can be more complicated, A chief estimates that he can have a house of villagers in forty days by employing fifteen villagers. After twelve days of work, the work is paused for one week, since he runs out of building materials. How many villagers must he adds so that the house can be completed in time?
The answer of the problem is :
To complete the work in forty days is requires fifteen villagers.
After twelve days of work by fifteen villagers, the remaining days are equal to 40 – 12 = 28 days.
After seven days paused, the remaining days are equal to 28 – 7 = 21 days, and the number of villagers is required is k person.
Now, the table is
Since the time (number of days) is decreased, the number of villagers must be increased.
Thus, the above problem is related to inverse proportions.
So, additional of villagers is twenty minus fifteen equals five.
There the example problem mathematics of solving problem in area of disasters.
Mathematics is our life and vice versa our life is mathematics. ^_^
NIM : 10305141040
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