A hospital ward must accommodate 56 patients so that each gets 2.2 m^2 of floor area and 8.8 m^3 of air space. If the room length is fixed at 14 m, find the required breadth and height.
Aptitude
Volume and Surface Area
Difficulty: Medium
Choose an option
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A8.8 m, 4 m
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B8.4 m, 4.2 m
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C8 m, 4 m
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D7.8 m, 4.2 m
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ENone of these
Answer
Correct Answer: 8.8 m, 4 m
Explanation
Introduction / Context:The ward must satisfy two constraints simultaneously: adequate floor area and adequate air volume. With a fixed length, we determine breadth from floor-area needs and then height from the volume requirement.
Given Data / Assumptions:
- Patients = 56.
- Per-patient floor area = 2.2 m^2.
- Per-patient volume = 8.8 m^3.
- Length L = 14 m.
Concept / Approach:
- Total floor area A = 56 * 2.2.
- Total volume V = 56 * 8.8.
- Let breadth = B and height = H. Then A = L*B and V = L*B*H.
Step-by-Step Solution:
A_total = 56 * 2.2 = 123.2 m^2With L = 14, B = A_total / L = 123.2 / 14 = 8.8 mV_total = 56 * 8.8 = 492.8 m^3L*B*H = 14 * 8.8 * H = 492.8 ⇒ H = 492.8 / 123.2 = 4.0 mVerification / Alternative check:Check both constraints: floor area = 14*8.8 = 123.2 m^2 ✓; volume = 14*8.8*4 = 492.8 m^3 ✓. Both satisfied exactly.
Why Other Options Are Wrong:
- 8.4 m, 4.2 m and others: Either floor area or volume misses the requirements.
- None of these: Not applicable since (8.8 m, 4 m) meets both constraints exactly.
Common Pitfalls:
- Confusing per-patient values with totals.
- Solving only the area constraint and forgetting to verify volume.
Final Answer:8.8 m, 4 m