2016 · Q44
A cubic metre of copper weighing 9000 kg is rolled into a square bar 9 m long. An exact cube is cut off from the bar. How much does the cube weigh ?
Elementary MathematicsMensuration
- A1000 kg
- B1000/3 kg
- C300 kg
- D500/3 kg
Explanation
The 9 m bar has cross-section 1/9 m², so its side is 1/3 m. The exact cube cut off has volume (1/3)³ = 1/27 m³. It therefore weighs 9000/27 = 1000/3 kg (option B).