1) How many cubic metres of earth must be dug out to sink a well22.5m deep and diameter 7m? A) $800m^{3}$ B) $845m^{3}$ C) $866.25m^{3}$ D) $832.5m^{3}$ Answer: Option CExplanation:Depthof the well=22.5m Volume of the well $=\pi r^{2}h$$=\frac{22}{7}\times \frac{7}{2}\times \frac{7}{2}\times 22.5$ $866.25m^{3}$
