Can you pls explain why too

Consider a cube that has sides of length l. now consider putting the largest sphere you can inside this cube without any point on the sphere lying outside of the cube. the volume ratio -volume of the sphere/ volume of the cube is 1. 5.2 × 10−1 2. 3.8 × 10−1 3. 1.9 4. 2.5 × 10−1 5. 3.8

The radius of the earth is two times the radius of the moon. what fraction of the volume of the earth is the volume of the moon?

Factor and solve to find roots x squared -x - 90 =0