Remember that this is a question tag, question tag formula should be:
Auxiliary verb + not + subject --- If the statement is positive
Auxiliary verb + subject --- if the statement is negative
- Logic, isn't it? (Positive adjective, negative QT)
- It makes sense, doesn't it? (Positive verb, negative QT)
- It's not true, is it? (Negative adjective, positive QT)
- You don't know, do you? (Negative verb, positive QT)
I say '...no?' quite a bit, but I have some French friends so maybe it's just that rubbing off.
There's something I like about the turn of phrase. It might just be that it's so short and simple.
I can see why you wouldn't want to use '...no?' if you're obviously not a native speaker, though: it might look as though you're importing bits of your own language inadvertently.
I was just marked wrong for using "Reasonable", even though "reasonable" is one of the three translations they actually give for "logique", (along with "sensible"). English speakers don't say "logical" very often, but we do say things like "that makes sense" and "that's reasonable" quite a bit. Here in France, "logique" is used very frequently, so it is a good word to know.