A reservoir is in the shape of a frustum of a right circular cone. The radii of its circular ends are 4 m and 8 m and its depth is 7 m. How many kilolitre of water (correct up to one decimal place) can it hold?(Take π = 22/7)
1
821.3
2
815.7
3
792.3
4
775.7
5
None of the above