If the radius of a sphere is increased by 50%, then its surface area will increase by:
Answer & explanation
Correct answer: option 2
50% = \(\frac{1}{2}\)
Original New
Radius 2 : 3
Radius 2 : 3
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Surface area (π r²) 4 : 9
Percentage increase in surface area = \(\frac{9 - 4 }{4}\) x 100%
= \(\frac{5}{4}\) x 100%
= 125%