It was believed that even numbers are unlucky.
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Explanation: </u>
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 
Answer:
stereotype
Explanation:
Stereotype: In social psychology, the term stereotype is defined as the tendency of an individual to develop mistaken ideas or beliefs that he or she can have about a particular group, person, or thing based on the outside appearance which may be considered as partly true or untrue.
Example: A man feels that women are less hardworking than men.
In the question above, the given statement represents the stereotype.