The total surface area of a hemisphere is $4158 \, cm^2$. Find its diameter in $cm$.

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

The radius and volume of a cylinder are $3.5\,cm$ and $2310\,cm^3$ respectively. Find its height in $cm$.

The areas of the three surfaces meeting at one vertex of a cuboid are $700 \, cm^2$,$300 \, cm^2$,and $525 \, cm^2$ respectively. Find the dimensions and volume of the cuboid.

$A$ 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 a hemispherical balloon increases from $6\,cm$ to $12\,cm$ as air is being pumped into it. The ratio of the surface areas of the balloon in the two cases is