A hollow spherical shell is made of a metal with a density of 6 g/cm3. If the internal and external radii of the shell are 8 cm and 9 cm respectively, find the weight of the shell in kilograms (Take π = 227).

Find the approximate volume and surface area of a sphere of radius 6 cm. (Use π = 227)

Ram has two spherical balls of radius 10.5 cm each and Meena has six spherical balls of radius 7 cm each. What is the total volume of the balls that Meena has?