$66 \text{ cm}^3$ of silver is drawn into a wire $1 \text{ mm}$ in diameter. The length of the wire in metres will be

$A$ right circular cylinder having diameter $21\, cm$ and height $38\, cm$ is full of ice cream. The ice cream is to be filled in cones of height $12\, cm$ and diameter $7\, cm$ having a hemispherical shape on the top. The number of such cones to be filled with ice cream is

$A$ large solid sphere is melted and moulded to form identical right circular cones with base radius and height same as the radius of the sphere. One of these cones is melted and moulded to form a smaller solid sphere. Then the ratio of the surface area of the smaller to the surface area of the larger sphere is

If each side of a cube is increased by $10 \%$,the volume of the cube will increase by (in $\%$).

$A$ cone of height $9 \, cm$ with diameter of its base $18 \, cm$ is carved out from a wooden solid sphere of radius $9 \, cm$. The percentage of the wood wasted is

The radius of a cylinder is made twice as large. How should the height be changed so that its volume remains unchanged?