Find the total surface area of a cylinder with diameter $28 \text{ cm}$ and height $50 \text{ cm}$. (in $\text{cm}^2$)

The radius of a cone is $15 \, cm$ and its slant height is $25 \, cm$. Find the curved surface area and the total surface area of the cone. $(\pi = 3.14)$

In $\triangle ABC$,$\angle B = 90^{\circ}$,$AB = 28 \, cm$,and $BC = 21 \, cm$. If the triangle is revolved about the side $AB$,find the curved surface area of the cone so obtained. Similarly,if the triangle $ABC$ is revolved about the side $BC$,find the curved surface area of the cone so obtained.

Write True or False and justify your answer in each of the following: $A$ cylinder and a right circular cone have the same base and the same height. The volume of the cylinder is three times the volume of the cone.

The radius of a sphere is $3.5\, cm$. Find the cost of plating gold on its surface at the rate of ₹ $150$ per $cm^{2}$. (in ₹)

Surface area of a cuboid = $\ldots \ldots \ldots$