Find the total surface area of a cone with diameter $6\, cm$ and slant height $11\, cm$. (in $cm^2$)

The total surface area of a cube is $96 \, cm^2$. The volume of the cube is (in $cm^3$)

In the auditorium,there are $20$ cylindrical pillars. Each pillar has a radius of $14 \, cm$ and a height of $5 \, m$. Find the cost of painting the curved surface of all the pillars at the rate of ₹ $120$ per $m^2$.

The volumes of two spheres are in the ratio $64: 27$. Find the ratio of their surface areas.

The radius and slant height of a cone are in the ratio of $2:7$. If its curved surface area is $704 \, cm^2$,find its radius $(r)$,slant height $(l)$,and height $(h)$.

State whether the following statement is True or False and justify your answer: If the radius of a cylinder is doubled and its height is halved,the volume will be doubled.