Question:
Based on the premise "8 billion pieces of advertising mail.", can we conclude that "A consistent number of pieces of advertising mail has been sent in the last year."?
****
Answer:
it is not possible to tell

Question:
Based on the premise "I doubt it.", can we conclude that "I have doubt."?
****
Answer:
yes

Question:
Based on the premise "thanks sir", can we conclude that "Thanks for doing that for me sir."?
****
Answer:
it is not possible to tell