Question

Earth's moon is the only place beyond the earth where humans have step foot. Moon influences human societies and cultures since time immemorial. Answer the following questions on the basis of following information about the moon and the Earth: "The diameter of the moon is approximately one-fourth of the diameter of the earth."

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

A cone is 8.4 cm high and the radius of its base is 2.1 cm. It is melted and recast into a sphere. The radius of the sphere is

The radius of a spherical balloon increases from 7 cm to 14 cm as air is being pumped into it. Find the ratio of surface areas of the balloon in the two cases.