why is there a / in the <img> tag question if there is no closing tag?

Question

The <img> is written without the / (forward slash) according to the reading material before the question, but when the test question is presented it asks "what tag is used to insert and image"? <___/> is how the answer is structured and I did receive a correct answer when inputing <img/> in the blank space. Is this a typo?

Answer 1

According to the XHTML syntax (which is more strict than HTML5) the self-closing tags should end with />
In HTML this is not mandatory but a good practice to follow.
http://xahlee.info/js/html5_non-closing_tag.html

Answer 2

Because there’s no closing tag, it’s “best practice” to include a forward slash. It’s not required, but encouraged