Practicing Success

Target Exam

CUET

Subject

General Test

Chapter

Quantitative Reasoning

Topic

Mensuration: 3D

Question:

If the radius of a sphere is increased by 2 cm, its surface area is increased by 464π cm². What is the radius of the original sphere? - 

Options:

14 cm

15 cm

28 cm

10 cm

Correct Answer:

28 cm

Explanation:

Increase in surface area = 4 \(\pi \) (r + 2)² - 4\(\pi \) r²

        464 \(\pi \) = 4 \(\pi \) ( 4r + 4)
       448 \(\pi \) = 16 \(\pi \) r 
                   r    = 28 cm