Volume of a sphere = 4/3 πr³
Volume of a sphere with radius 10 inches = 4/3π(10)³ in³
Volume of a sphere with radius 20 inches = 4/3π(20)³ in³
Volume added = 4/3π(20)³ - 4/3π(10)³ = 29321.5 in³ (nearest tenth)
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Answer: Volume = 2932`.5 in³ (Answer C)
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