Difficulty: Medium
Correct Answer: 68
Explanation:
Introduction / Context:
The problem states the area is increased by “1 1/5 times” the original by changing length only. In standard wording, “increased by 1 1/5 times” means the increase equals 1.2 of the original, so the new area becomes 1 + 1.2 = 2.2 times. However, many aptitude items intend “becomes 1 1/5 times,” i.e., 1.2 times. We apply the Recovery-First policy and adopt the widely used interpretation: new area = 1.2 * original, since the answer options align with this reading.
Given Data / Assumptions:
Concept / Approach:
With breadth fixed, new length L' = A' / B. Compute perimeter P' = 2(L' + B). This directly uses rectangle area and perimeter definitions under the clarified assumption.
Step-by-Step Solution:
Verification / Alternative check:
Why Other Options Are Wrong:
Common Pitfalls:
Final Answer:
68.
Discussion & Comments