Question

A well of diameter 7 m and depth 14 m is dug and the earth removed is spread evenly as a platform on a rectangular plot of land 28 m long and 21 m wide. Find the height of the platform.

Answer 1

By volume conversation $\Rightarrow$

$\pi r^{2}h=lb{h}_1$

$\frac{22}{7}\times \frac{7}{2}\times \frac{7}{2}\times 14=28\times 21\times h_1$

$h_1=\frac{22}{7}\times \frac{7}{2}\times \frac{7}{2}\times 14\times 28\times 21$

$=\frac{11}{2}m$