Difficulty: Easy
Correct Answer: 42.24%
Explanation:
Introduction / Context:
Area scales as the square of a linear dimension. A decrease in radius reduces surface area by the square of the scale factor.
Given Data / Assumptions:
Concept / Approach:
Compute ratio S′/S = (r′/r)^2 = (0.76)^2 and convert to percent decrease.
Step-by-Step Solution:
Verification / Alternative check:
Square 76/100 precisely to avoid rounding errors; 76^2 = 5776; move decimal: 0.5776.
Why Other Options Are Wrong:
Common Pitfalls:
Subtracting 24% twice or assuming area decreases by exactly double (48%).
Final Answer:
42.24%
Discussion & Comments