I need some help with this equation.

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?

Which of the following is an example of a rational number? a. π b. √ 9 c. √ 8 d. 3.8362319

The moats separating people from the animals are 5 m wide for lions and 4 m wide for the elephants. if the lion’s moat is 4 m deep, how deep should the elephants’ moat be?