Translation:My older brother's nose is like father's.
The course was done quickly (thanks!). You can help remove the bugs in this beta version by reporting suggested translations.
Here's an example of a sentence where the Chinese doesn't include 的 between two family members: 我哥哥。The sentences are currently a bit random regarding this (I keep getting marked wrong for omitting it in many other sentences). Personally I'd never use it with inalienable nouns like family members and body parts, but I'm not sure if it's optional in these cases or not? Well I guess Duo is telling me that it's optional.
哥哥 (gēgē) means older brother or big brother. So yes, your answer should be correct, I think. I've been consulting my chinese classmates on lots of these. This chinese course is very new, so naturally there are lots of bugs. We can all contribute to its improvement, though, by reporting issues. Its not perfect, but i still find it very helpful and useful. Cheers.
Over 60 of just my own reported suggestions have been incorporated by the moderators of the Chinese tree. I am sure others have contributed many, many more. They are doing great work!