2021 · Q101
Which one of the following is the average of all prime numbers between 21 and 55 ?
General Mental Ability, Quantitative Aptitude and StatisticsNumber system and arithmetic
- A35.85
- B36.71
- C38.00
- D39.00
Explanation
The primes strictly between 21 and 55 are 23, 29, 31, 37, 41, 43, 47 and 53 — eight numbers summing to 304. Their average is 304 ÷ 8 = 38.00. Hence (C) 38.00 is correct.