If the surface areas of two spheres are in the ratio of 49 : 81, then find the ratio of their volumes.
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. 343 : 729.
Ratio of the surface areas of two spheres = (Ration of radius of two spheres)2
Ratio of volume = (Ratio of radius)3
According to the given question,
(r1/r2)2 = 49/81
⇒ r1/r2 = 7/9
So, Ratio of volumes = (r1/r2)3
⇒ (7/9)3 = 343 : 729