Five consecutive even numbers, the smallest — Aptitude
Five consecutive even numbers, the smallest: The average of five consecutive even numbers is 24. What is the… Answer and worked solution on CodeKairo.
- Topic: Averages
- Section: Quantitative Aptitude
- Difficulty: Easy
- Time target: 40 seconds
Question
The average of five consecutive even numbers is 24. What is the smallest of them?
Options
- 18
- 20
- 22
- 26
Show the answer and the worked solution
Correct answer: B. 20
Worked solution
- The middle number is 24, so the numbers are 20, 22, 24, 26, 28.
- The smallest is 20.
Answer: 20.
The idea
Evenly spaced with an odd count: middle term = average, then step out by the common difference.
Shortcut. Smallest + largest = 2 × 24 = 48 and they are 8 apart (four steps of 2), so the smallest is (48 − 8) ÷ 2 = 20.
Common trap. "22" — stepping down only one even number from 24; the middle of five terms has two terms below it.