What number would replace the question mark (?) in the series given below? 11,…
2023
What number would replace the question mark (?) in the series given below?
11, 13, 17, 19, 23, ?, 31, 37
Answer: D. 29 — ConceptA prime number is a whole number greater than 1 with exactly two positive divisors: 1 and the number itself. A sequence can be tested for a…
- A.
28
- B.
25
- C.
27
- D.
29
Show answer & explanation
Correct answer: D
Concept
A prime number is a whole number greater than 1 with exactly two positive divisors: 1 and the number itself. A sequence can be tested for a prime-number pattern by checking each term against this definition.
Application
The given terms 11, 13, 17, 19 and 23 are consecutive prime numbers.
The next prime after 23 is 29 because none of 2, 3 or 5 divides 29.
The following primes are 31 and 37, matching the remaining terms.
Cross-check
The composite numbers between 23 and 31 are 24, 25, 26, 27, 28 and 30; each has a divisor other than 1 and itself. Therefore the missing term is 29.