Given Data

1. Given numbers: 23, 29, 37, 39

Question

Which number does not belong to the group?

Answer

39.

Solution

1. Examine the mathematical properties of each given number:
2. 23 is a prime number (divisible only by 1 and 23).
3. 29 is a prime number (divisible only by 1 and 29).
4. 37 is a prime number (divisible only by 1 and 37).
5. 39 is a composite number (divisible by 1, 3, 13, and 39).
6. Because 39 is composite while the rest are prime numbers, 39 is the odd one out.