2022 · Q66
A spherical ball of lead 6 cm in diameter is melted and recast into three spherical balls. The diameters of the balls are 2 cm, 4 cm and x cm. Which one of the following is correct?
Elementary MathematicsMensuration
- A5 cm
- B5.2 cm
- C5.4 cm
- D5.6 cm
Explanation
Volume conservation: 3³ = 1³+2³+(x/2)³ gives (x/2)³ = 18, so x ≈ 5.24, nearest to 5.2 cm. Hence the keyed option is B.