la tinne le tien

Question

why is it feminine in this case?

Accepted Answer

Kevin, in which case ? 
 
 Link is to the lesson, not a specific example. 
It will be feminine - la tienne- whenever the ‘possession’ noun, whether for something physical or otherwise, is feminine grammatical gender and singular.

Answer

Bonjour Kevin,
Maarten is correct.
Here are 2 examples:

Mon vélo est neuf. Et le tien ? = My bike is brand new. What about yours?
Cette voiture est superbe. C'est la tienne ? = This car is amazing. Is it yours?

A few examples with"le tien/etc" have now been added to the lesson.
I hope this is helpful.
Bonne journée !

Answer

ooops la tienne, typo

Answer

Thanks all I didn't know the example I was referring too wasn't linked - I'm too used to Duolingo where it is; which of course is much more helpful.  That said I much prefer this course overall. I know all that has been pointed out; in the example to which I referred I couldn't determine why the answer assumed a feminine gender.

Answer

La tienne , letien is for both his or her so it depends on the gender of the noun