The height of a cone is 42 cm. A smaller cone is cut off at the top by a plane parallel to the base, and its volume is 18 of the volume of the given cone. At what height from the base is the section cut?

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?