If I recall correctly, it says somewhere that we each have a predefined number of words to speak, after which we die. (The idea being that one should be careful not to speak unnecessarily.) Assuming ...
For example, if one's parent died on 1 Nissan, and was buried on 2 Nissan, what is the last day on which kaddish would be said for them?
Prior to the Mabul people lived for hundreds of years. After the Mabul lifespans shortened although we see that the Avos lived in the 180 year range. In the Pasuk in Tehilim we say Yemei Shenoseinu ...