$A$ cone of height $7 \text{ cm}$ and base radius $3 \text{ cm}$ is carved from a rectangular block of wood $10 \text{ cm} \times 5 \text{ cm} \times 2 \text{ cm}$. The percentage of wood wasted is:

$A$ cylindrical tower is $5 \, m$ in diameter and $14 \, m$ high. The cost of white washing its curved surface at $50$ paise per $m^{2}$ is (in $Rs.$)

$A$ right circular cone is exactly fitted inside a cube in such a way that the edges of the base of the cone are touching the edges of one of the faces of the cube and the vertex is on the opposite face of the cube. If the volume of the cube is $343 \, c.c.$,then what approximately is the volume of the cone? (in $c.c.$)

If the radius of a sphere is doubled,then its volume is increased by (in $\%$)

The ratio of radii of $2$ right circular cylinders is $2:3$ and their heights are in the ratio $5:4$. The ratio of their curved surface area is

$A$ sphere is melted to form a cylinder whose height is $4 \frac{1}{2}$ times its radius. What is the ratio of the radius of the sphere to the radius of the cylinder?