Difficulty: Easy
Correct Answer: 30
Explanation:
Introduction / Context:This problem uses equivalence of consumption between men and children. If total food is sufficient for 120 men (or 200 children) for the same period, we can convert children-consumed food into the “men” equivalent and then subtract from the total men-capacity to find how many men can still be served.
Given Data / Assumptions:
Concept / Approach:Equate consumption rates: 120 men ≡ 200 children ⇒ 1 man ≡ 200/120 = 5/3 children ⇒ 1 child ≡ 3/5 man. Convert 150 children to men-equivalents and subtract from 120 to get remaining men-capacity.
Step-by-Step Solution:
Men-equivalent of 1 child = 3/5 manMen-equivalent of 150 children = 150 * 3/5 = 90 menRemaining men-capacity = 120 − 90 = 30 menVerification / Alternative check:Children remaining capacity: 200 − 150 = 50 children. Convert 50 children back to men: 50 * 3/5 = 30 men—consistent from either direction.
Why Other Options Are Wrong:
Common Pitfalls:Inverting the equivalence (treating 1 child ≡ 5/3 men) or forgetting that the total food corresponds to the same time period for both groups.
Final Answer:30
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