A spherical balloon has a radius of 9 inches. If the radius is decreased by , by what factor does the volume decrease?
- (correct answer)
Explanation: Original radius is 9 inches. Decreased by means the new radius is inches. Original volume: . New volume: . The ratio of original to new volume is . So the volume decreases by a factor of . Choice A uses linear scaling. Choice B gives the reciprocal. Choice D incorrectly uses .