- A fort had provision of food for 150 men for 45 days.
- After 10 days, 25 men left the fort.
- The number of days for which the remaining food will last can be figure out in this way.
Explanation
Two given entities here are
- Men
- Days
To determine the relation here, let suppose; Number of days for which the remaining food will last = y
Case
As we know that;
Men Days
150 35
125 y
- Provision of food for days decreases as men increases.
- Provision of food for days increases as men decreases.
This clearly indicates that there is inverse relation.
Direct/Indirect relation tells how the equation will be written.
150 : 125 :: y : 35 ________ (A)
After simplifying equation (A), we can easily figure out the value of y (y = 42)
To Find
Number of days for which the remaining food will last = ?
Solution
Method I
Let suppose
Number of days for which the remaining food will last = y
Men Days
150 35
125 y
Relation between men and days is inverse, so;
150 : 125 :: y : 35
150 x 35 = y x 125
5250 = 125y
5250/125 = y
y = 42
Number of days for which the remaining food will last = 42 days answer
Method II
150 men had provision of food = 35 days
1 man had provision of food = 35 x 150 days
1 man had provision of food = 5250 days
125 man had provision of food = 5250/125 days
125 man had provision of food = 42 days
Number of days for which the remaining food will last = 42 days answer
Conclusion
A fort had provision of food for 150 men for 45 days. After 10 days, 25 men left the fort. The remaining food will last for 42 days.