Question

How many cubic meters of soil must be dug out to make a well 20 meters deep and 2meters in diameter

Answer 1

soil must be dug = volume
$v = \pi \times {r}^{2} \times h$
radius = diameter / 2
radius = 2 / 2 metres
radius = 1 metre
height = 20 metre
volume = 22/7 * (1 metre)^2 * 20 metre
volume = 22/7 * 1 metre^2 * 20 metre
volume = 440/7 metre^3
volume = 62.83 metre.^3