General Aptitude TestQuantitative ReasoningMensuration: 2D/3D

If the total surface area of a sphere of radius r cm is equal to the…

If the total surface area of a sphere of radius r cm is equal to the total surface area of a cube of side s cm, which of the following is true?

Answer & explanation

Correct answer: option 4

We have,

Total surface area of a sphere = 4πr²

Total surface area of a cube = 6a²

We have,

According to the question,

4πr² = 6s²

= 44r² = 21s²

= r² : s² = 21 : 44

So the, value of r will be in between 4 and 5 and the Value of s will be between 6 and 7

So, from this we can say r < s