Concept:Prime numbers have only two factors (1 and itself), while composite numbers have more than two factors.
Explanation:11 is divisible only by 1 and 11. So it is a prime number.
17 is divisible only by 1 and 17. So it is a prime number.
23 is divisible only by 1 and 23. So it is a prime number.
27 is divisible by 1, 3, 9, and 27. So it is a composite number (
27=3×3×3).
Three numbers (11, 17, 23) are prime, but 27 is not prime. Hence, 27 is the odd one out.
Answer:Option D (27)