Question

If the volume of a sphere is equal to the volume of a cube, what is the ratio of the edge of the cube to the radius of the sphere?
A) 1.16
B) 1.53
C) 1.61
D) 2.05

Answer 1

Answer: The answer is (C) 1.61.

Step-by-step explanation: Given that the volume of a sphere is equal to the volume of a cube. We are to find the ratio of the edge of the cube to the radius of the sphere.

Let, 'r' be the radius of the sphere and 'e' be the edge of the cube. Then, the volume of the sphere is given by

$V_s=\dfrac{4}{3}\pi r^3,$

and the volume of the cube is

$V_c=e^3.$

According to the question, we have

$V_s=V_e\\\\\Rightarrow \dfrac{4}{3}\pi r^3=e^3\\\\\\\Rightarrow \dfrac{4}{3}\times\dfrac{22}{7}r^3=e^3\\\\\\\Rightarrow 88r^3=21e^3\\\\\Rightarrow 4.44r=2.75e\\\\\Rightarrow \dfrac{e}{r}=\dfrac{4.44}{2.75}\\\\\Rightarrow e:r=1.61.$

Thus, the correct option is (C) 1.61.