- A4 times
- B2 times
- C8 times
- D16 times
Step-by-Step Solution
Surface area is proportional to . Radius doubles (7 to 14), so area becomes times.
Answer: A) 4 times
A balloon is roughly a sphere. When inflated, its radius increases from 7 cm to 14 cm.
By what factor does its surface area increase?
Class 9Surface Area of a SphereMensuration
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