tense - How to describe duration of, and duration since, a finished past event?

If I ate from 7:00 until 7:30am,

1. 
   

   At 7:10, could I say

   
   

   
   

   I am eating for 10 minutes?

   
   

   
   


2. 
   

   At 7:40, could I say

   
   
   

   
   

   I ate for 30 minutes, 10 minutes ago?