2021 · Q70
3 cubes each of volume 343 cm³ are joined end to end. What is the total surface area of the resulting cuboid ?
Elementary MathematicsMensuration
- A343 cm²
- B350 cm²
- C686 cm²
- D700 cm²
Explanation
Each cube has side ∛343 = 7 cm; joined end to end they form a 21 × 7 × 7 cuboid. Its total surface area is 2(21·7 + 7·7 + 21·7) = 2 × 343 = 686 cm². This is option (c).