Choose the number which is different from others in the group:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → 15
15 is different from the others in the group.
- 11, 13, and 17 are prime numbers (divisible only by 1 and themselves).
- 15 is not a prime number (it is composite: 15 = 3 × 5).
Thus, 15 is the odd one out.