It was believed that even numbers are unlucky.
Explanation:
It is an old superstitious belief that even numbers are unlucky. In respect of the same superstition, a gun salute is set off odd numbers.
It is a gesture of bestowing great honor on a significant individual. Since long back in history, symbolism has been denoted to every numerical known. Hence, firing a gun for a certain of an odd number of times symbolizes varied kinds of respect in every country.
Some countries fire shots 21 times because number seven is sacred and lucky. Hence [tex]7 \times 3 = 21.[/tex]
