Difficulty: Easy
Correct Answer: 384 cm2
Explanation:
Introduction / Context:
For a cube, volume and surface area are functions of the side length a. If the volume is known, find a as the cube root, then compute surface area as 6a^2. This is a straightforward application of cube geometry formulas.
Given Data / Assumptions:
Concept / Approach:
Take the cube root of 512 to find a; then square a and multiply by 6 to obtain S.
Step-by-Step Solution:
a = ∛512 = 8 cmS = 6a^2 = 6 * 8^2 = 6 * 64 = 384 cm^2
Verification / Alternative check:
Compute volume from a = 8: 8^3 = 512, confirming side length.
Why Other Options Are Wrong:
64 cm^2 is one face area (a^2) times 1; 256 cm^2 is 4a^2; 512 cm^2 equals 8a^2; only 384 cm^2 equals 6a^2.
Common Pitfalls:
Accidentally using 6a instead of 6a^2; mixing units (keeping “cm” vs “cm^2”).
Final Answer:
384 cm2
Discussion & Comments