Sphere radius changed: percent change in surface area or volume

This type of question, asked 3 times: 29 Jan 2022 Tier II, 3 Feb 2022 Tier II, 2 Mar 2023 Tier II. All 3 questions below, oldest first.

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Question 1
29 Jan 2022 Tier II
24 $The radius of a spherical balloon is inflated from 3.5 cm to 4.9 cm by pushing air into it. What is the percentage increase in the volume of the original balloon?$
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Question 2
3 Feb 2022 Tier II
47 $The radius of a spherical balloon is inflated from 7 cm to 10.5 cm. The percentage increase in its surface area is:$
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Question 3
2 Mar 2023 Tier II
15 $If radius of a sphere is decreased by 48%, then by what percent does its surface area decrease?$
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Question 1