The internal radius of a metallic pipe is 2 cm and its external radius is 2.7 cm. If the length of the pipe is 10 cm, then find the volume of the metal used for this pipe. (Use 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?