A well with inner diameter 8 m is dug 14 m deep. Earth take out of its has been evenly spread all around it to a width of 3 m form an embankment. The height of the embankment will be :

Volume of earth dug out :
$$\eqalign{ & = \left( {\frac{{22}}{7} \times 4 \times 4 \times 4} \right){{\text{m}}^3} \cr & = 704\,{{\text{m}}^3} \cr} $$
Area of embankment :
$$\eqalign{ & = \frac{{22}}{7} \times \left( {{7^2} - {4^2}} \right) \cr & = \left( {\frac{{22}}{7} \times 11 \times 3} \right){{\text{m}}^3} \cr & = \frac{{726}}{7}{{\text{m}}^3} \cr} $$
Height of embankment :
$$\eqalign{ & = \left( {\frac{{{\text{Volume}}}}{{{\text{Area}}}}} \right) \cr & = \left( {\frac{{704 \times 7}}{{726}}} \right){\text{m}} \cr & = \frac{{224}}{{33}}{\text{m}} \cr & = {\text{ 6}}\frac{{26}}{{33}}{\text{m}} \cr} $$