This question still needs an edit and apparently has been flagged a few times.
The existing answer is incorrect for port 53
https://community.spiceworks.com/questions/2999/explanation?source=superfeed-daily-challenge
@josh-j-spiceworks
7 Spice ups
Fixed incorrect portion of correct answer (SSL listed instead of DNS).
3 Spice ups
Cheers. Thankfully the other sets of answers are easy to cross out.
2 Spice ups
Can you fix the grammer issue in the question as well?
Should be “Well known”, not “Well know”.
2 Spice ups
Changed to:
Well-known ports 21, 22, 25, and 53 are used for which services?
2 Spice ups