**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?

**Solution:**

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 = π*r2h* = $\frac{22}{7}(3.5)^{2}(20) \mathrm{m}^{3}=770 \mathrm{~m}^{3}$

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

Height $=\frac{770}{22 \times 14}=2.5 \mathrm{~m}$

Thus, the height of the platform is 2.5 m.