Question

- The radius of a sphere is increased by 10% so its surface area increase by what percent
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Answer 1

Answer:

21%

Step-by-step explanation:

let the radius of sphere of r

Old s.a of sphere = 4πr²

new radius = 110/100*r

=11/10r

New surface area = 4π(11r/10)²

Increase percent = (4π(11r/10)²-4πr²/4πr²)*100

= (4πr²(121/100 - 1)/4πr²)*100

= 21/100*100

= 21%

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