2020 · Q80
How many cubic metre of earth is to be dug out to dig a well of radius 1.4 m and depth 5 m?
Elementary MathematicsMensuration
- A30.2 cubic metre
- B30.4 cubic metre
- C30.6 cubic metre
- D30.8 cubic metre
Explanation
Volume = πr²h = π × 1.4² × 5 = 9.8π = 9.8 × 22/7 = 30.8 m³. With π = 22/7, this is 9.8 × 22/7 = 30.8. So 30.8 m³ of earth was dug out.