Question

If the ratio of volumes of two spheres is 1: 8, then the ratio of their surface areas is :

A. 1 : 2 

B. 1 : 4 

C. 1 : 8 

D. 1 : 16

Answer 1

Option : (B)

Ratio of volume of spheres = (ratio of radius)³ 

Given, 

ratio of volumes of two spheres is 1: 8 

⇒ (ratio of radius)³ = 1 : 8 

⇒ ratio of radius = 1 : 2 

Ratio of surface area = (ratio of radius)² 

⇒ Ratio of surface area = 1 : 4