Question

A well is dug 20 m deep and it has a diameter of 7 m. The earth which is so dug out is spread out on a rectangular plot 22 m long and 14 m broad. What is the height of the platform so formed?

Answer 1

Height of the well = h m = 20 m
Diameter of the well = d m =7 m
Radius of the well = r m = 3.5 m
Volume of the well = πr²h = 22(3.5)²(20 ) m³= 770 m³
​ 7
Volume of the well = Volume of the rectangular plot
Length of the rectangular plot = 22 m
Breadth of the rectangular plot =14 m
Volume of the rectangular plot = 770 m³ = (Length$\times$ Breadth $\times$Height) of the rectangular plot
$\mathrm{Height}=\frac{770}{22\times 14}=2.5\mathrm{m}$

Thus, the height of the platform is 2.5 m.