Question

A well of diameter 14m is dug 8m deep. The earth taken out of it is evenly spread all around it to a width of 21 m to form an embankment. Find the height of the embankment( in cm).

• A. 48.2
• B. 53.3
• C. 50
• D. 57.5

Answer 1

The correct option is B

53.3

Volume of earth dug out from the well = $\pi r^{2}h=\frac{22}{7}\times 7\times 7\times 8=1232m^3$

Area of the embankment = $\frac{22}{7}\times (R^2-r^2)=\frac{22}{7}\times \left((28{)}^2-(7{)}^2\right)m^2=\frac{22}{7}\times 35\times 21=2310m^2$ .

Height of the embankment = $\frac{Volumeofearthdugout}{areaofembankment}$ = $\frac{1232}{2310}\times 100cm$

= 53.3 cm