1 .He lived to be hundred years old.

2. He lived to be a hundred years old

First of all, I wonder I should put 'a' before hundred or not.



3. I have a story to write.

4. I have a story to write about.

5. I have a house to live.

6. I have a house to live in.


Second, I want to know it is not grammatical to say like 3 and 4.


Thank you so much and have a good weekends.