Question

Which sentence is correct?

The historic building is now more than ninety nine years old.


The historic building is now more than ninetynine years old.


The historic building is now more than ninety-nine years old.


The historic building is now more than ninety-nine-years old.

Answer 1

The third sentence, numbers usually have a hyphen

Answer 2

C: The historic building is now more than ninety-nine years old.

Ninety-nine is one, spelt like this. Two, when you are adding years after a number a dash does not follow the final digit. Thus, that answer is Choice C.