In a fort there was a food provision for 120 men for 200 days. After 5 days, 30 men moved to another place. How long will the remaining food last?
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → 260 days
A fixed stock of food is measured in man-days: men × days the food lasts. The stock does not change when men leave, so fewer men make the same food last longer, in inverse proportion.
After 5 days, the food left would last the 120 men \(200-5=195\) more days
Food left \(=120\times195=23400\) man-days
Men left after 30 move away \(=120-30=90\)
Days the food now lasts \(\displaystyle =\frac{23400}{90}=260\) days