Question

The diameter of a sphere is decreased by 25%. By what per cent does its curved surface area decrease?

Answer 1

15% I am not sure
Hope it helps you

Answer 2

let the original diameter be x
the diameter is decreased by 25% of the original one so the the new diameter = x - 25% of x
=3x/4
surface area of a sphere according to its original diameter is equals to 4πr²
=4×π×x²
= 4x²π
surface area of sphere according to its new diameter that is 3 X upon 4 is equals to 4πR²
= 4×π×(3x/4)²
=27x²π/16
percentage decrease will be new surface area / original surface area × 100
=(27x²π/16)/4x²π×100
= 27/64×100
=42.18%

I hope this will help you and please mark me as brainliest...