f radius of a sphere is decreased by 48 then by what percent does its surface area decrease ........

Quantitative Aptitude (CGL) Mensuration 2D

f radius of a sphere is decreased by 48%, then by what percent does its surface area decrease?

This questions was previously asked in

SSC CGL Tier II Paper 1 (02.03.2023)

82.91%

72.96%

78.98%

86.26%

- The formula for the surface area of a sphere is \(4\pi r^2\), where \(r\) is the radius.

- If the radius decreases by 48%, it becomes \(0.52r\).

- The new surface area is \(4\pi (0.52r)^2\).

- Simplifying, the new surface area is \(4\pi \times 0.2704r^2\).

- The new surface area is 27.04% of the original.

- The surface area decreases by 100% - 27.04% = 72.96%.

Correct Answer: Option 2, 72.96%

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