Identify the odd one:
3, 5, 7, 11, 13, 17, 19, 21

Question

Accepted Answer

1. Check each number: 3, 5, 7, 11, 13, 17, 19 are all prime numbers.

2. $21$ is not prime because $21 = 3 	imes 7$, so it is composite.

3. Therefore the odd one out is $21$, which is option **(a)**.

FINAL_ANSWER: a

Answer

Answer

Answer