Certain quantity of food is sufficient for certain number of men for 13 days. After 1 day 2/5 of them desert how long will the food now last?
Correct answer: A. 20 days
- A. 20 days
- B. 25 days
- C. 18 days
- D. 16 days
Explanation
After 1 day, the remaining food represents 12 person-days for every original person, because the total supply was 13 person-days and 1 person-day has been used. If 2/5 desert, 3/5 remain, so the remaining duration is 12 person-days ÷ (3/5 person) = 20 days. The likely mistake is choosing 25 days by applying the 3/5 factor to the original 13 days instead of first subtracting the day already used.
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