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

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 $(h)$.

$A$ cuboidal closed tank of iron sheet is made having $10 \, m$ length,$8 \, m$ breadth,and $3 \, m$ height. Determine the cost of iron sheet used at the rate of $₹ 50$ per $m^2$. (in $₹$)

The radius of the base of a cone is $7 \, cm$ and its height is $30 \, cm$. Find the volume of a cone (in $cm^3$).

The height of a cone is $9 \, cm$. The area of the base is $1386 \, cm^2$. Find its volume (in $cm^3$).

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