If numerical value of curved surface area of a solid sphere is three times of its volume the length of radius is

The whole surface area of a solid hemisphere with length of 7 cm radius is

If the ratio of curved surface areas of two solid spheres is 16 : 9, the ratio of their volumes is

Let us write whether the following statements are true of false.

i. If we double the length of radius of a solid sphere, the volume of sphere will be doubled.

ii. If the ratio of curved surface areas of two hemispheres is 4 : 9, the ratio of their lengths of radii is 2 : 3.

Let us fill in the blanks.

i. The name of solid which is composed of only one surface is _______.

ii. The number of surfaces of a solid hemisphere is ___________.

iii. If the length of radius of a solid hemisphere is 2r units, its whole surface area is __________ π r² sq units.