Question

The height of a right circular cylinder is 10.5 m. Three times the sum of the areas of its two circular faces is twice the area of the curved surface. Find the volume of the cylinder.

Answer 1

It is known that three times the sum of the areas of the two circular faces, of the right circular cylinder, is twice the area of the curved surface.
Hence, it can be written using the following formula:
3 (2πr²) = 2(2πrh)
3πr² = 2πrh
3r = 2h
It is known that the height of the cylinder (h) is 10.5 m.
Substituting this number in the equation:
3r = 2(10.5)
r = 7 m

Volume of the cylinder = πr²h
                             = 22 (7²) (10.5)
                                7
                             = 1617 m³
Thus, the volume of the cylinder is 1617 m³.