Doubling the edge of a cube — Mensuration Aptitude Question
Doubling the edge of a cube: If the edge of a cube is doubled, by what factor does its volume increase? Answer and worked solution on CodeKairo.
- Topic: Mensuration
- Section: Quantitative Aptitude
- Difficulty: Easy
- Time target: 40 seconds
Question
If the edge of a cube is doubled, by what factor does its volume increase?
Options
- 2
- 4
- 6
- 8
Show the answer and the worked solution
Correct answer: D. 8
Worked solution
- Volume ∝ a³, so doubling the edge multiplies the volume by 2³ = 8.
Answer: 8.
The idea
Volumes scale as the cube of any linear change. The surface area, meanwhile, would only quadruple.
Shortcut. Picture a 2 × 2 × 2 stack: a cube with doubled edges is built from 8 of the original cubes.
Common trap. 4 — squaring the factor as for area; volume has three dimensions, so 2³.