V1 = volume of old sphere V1 = (4/3)*pi*r^3 V1 = (4/3)*pi*10^3 V1 = (4000/3)pi V1 = 4188.7902047864 <<--- this is approximate
V2 = volume of newsphere V2 = (4/3)*pi*r^3 V2 = (4/3)*pi*5^3 V2 = (500/3)pi V2 = 523.598775598299 <<--- this is approximate
Subtract volumes to find that... Amount of volume lost = V1 - V2 Amount of volume lost = 4188.7902047864 - 523.598775598299 Amount of volume lost = 3665.1914291881 Amount of volume lost = 3665
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Final Answer: 3665 ft^3 (cubic feet) So the answer is choice B)