A conical tent was erected by the army at a base camp with a height of 3 m and base diameter of 8 m. If every person requires 3.5 m3 of air, then how many persons can be seated in that tent approximately?

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?