$A$ 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

$A$ cistern of dimensions $2.4 \, m \times 2.0 \, m \times 1.5 \, m$ takes $2 \, \text{hours} \, 30 \, \text{minutes}$ to get filled with water. The rate at which water flows into the cistern is

Calculate the number of bricks,each measuring $25 \, cm \times 15 \, cm \times 8 \, cm$,required to construct a wall with dimensions $19 \, m \times 4 \, m \times 5 \, m$,when $10 \%$ of its volume is occupied by mortar.

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

$A$ 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?

$A$ circus tent is cylindrical to a height of $3\, m$ and conical above it. If its diameter is $105\, m$ and the slant height of the conical portion is $53\, m$,calculate the length of the canvas $5\, m$ wide required to make the tent. (in $m$)