Volume of a cylinder — Mensuration Aptitude Question
Volume of a cylinder: What is the volume of a cylinder with radius 7 cm and height 10 cm? (Take π = 22/7.) Answer and worked solution on CodeKairo.
- Topic: Mensuration
- Section: Quantitative Aptitude
- Difficulty: Easy
- Time target: 40 seconds
Question
What is the volume of a cylinder with radius 7 cm and height 10 cm? (Take π = 22/7.)
Options
- 1,440 cm³
- 1,540 cm³
- 1,650 cm³
- 1,760 cm³
Show the answer and the worked solution
Correct answer: B. 1,540 cm³
Worked solution
- V = πr²h = 22/7 × 7 × 7 × 10 = 22 × 7 × 10 = 1,540 cm³.
Answer: 1,540 cm³.
The idea
Base area × height for any prism or cylinder. Cancel the 7 in π = 22/7 against the radius before multiplying.
Shortcut. A radius of 7 gives the stock base area 154 cm² (22/7 × 49), so the volume is 154 × 10 = 1,540 cm³.
Common trap. 1,440 cm³ — recalling the r = 7 base area as 144 instead of 154 and multiplying by 10; 22/7 × 49 is 154.