What is the difference between ο ελάχιστος and το ελάχιστο? They are both used as nouns in the examples.
are there any practical differences in usage between this meaning and "ο μεγαλύτερος και ο μικρότερος"?
I think it'll be easier with some examples:
1)The oldest/youngest sister: Η μεγαλύτερη/μικρότερη αδερφή
2)The biggest/smallest portion: Either is fine.
3)It was the least I could do: Ήταν το ελάχιστο που μπορούσα να κάνω.
4)The biggest problem/fear: Το μεγαλύτερο πρόβλημα/Ο μεγαλύτερος φόβος
5)The local maximum/minimum (mathematics): Το τοπικό μέγιστο/ελάχιστο
Hope this helps ;)
This sentence is included in the alternatives, so we need a screenshot. Still, it's not the best translation possible, take a look at my examples above, maybe they can be of help.
Edit: This alternative has now been deleted, it's better like this (I wrote this as a different comment so that you get a notification).