The surface area of a sphere is $2464 \, cm^2$. Find its diameter in $cm$.

How many square metres of canvas is required for a conical tent whose height is $3.5 \, m$ and the radius of the base is $12 \, m$ (in $, m^{2}$)?

Total surface area of a hemisphere $= \dots$

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.

State whether the following statement is True or False and justify your answer:
$A$ cone,a hemisphere,and a cylinder stand on equal bases and have the same height. The ratio of their volumes is $1: 2: 3$.