Geometry

Question Analysis:
Compares two possible cylinder formations.

Key Concept Explanation:
Circumference becomes the cylinder's base circumference.

Step-by-Step Solution:
Option 1 (20cm circumference):
C = 2πr = 20 → r = 10/π
V = π(10/π)²(30) = 3000/π cm³
Option 2 (30cm circumference):
C = 2πr = 30 →  r = 15/π
V = π(15/π)²(20) = ...