Statistics problem

I am currently trying to work out an answer to a stats questions so I can include appropriate costs for my client. The scenario is this: A new website adds 229 articles per day My code will visit this site and check each article on the following basis 1. Check every 10 minutes for articles (Let's assume all articles appear at midnight). 2. There is a 50% chance that after 1 hour an article will have been changed/revised. If this is the case, we make a note to revisit the article again in 1 hour. 3. If the article hasn't changed, we make a note to check it again in 10 hours. This is the basic premise. With the following rules. 1. If an article hasnt changed, we wait longer next time on the following steps 1hour, 10 hours, 1 day, 3 days, 7 days, never. 2. If an article has changed, we wait a shorter time. ie. if we were meant to check an article after 1 day and it has changed, we check again in 10 hours, if it hasnt we check again in 3 days. There is also the change probability at the following steps 1 hour = 50% 10 hours = 20% 1 day = 5% 3 days = 2 % 7 days = 1% The question I have is, given 229 new articles per day, how many article checks do we need to make in a 31 day period? I hope this makes sense, I really hope you can help!