Good question, nobody really knows because the search engines keep very quiet about that sort of thing.
As a rule of thumb we can assume that "link juice" is divided equally between every link on the page (probably not accurate but good enough for our purposes here). What happens after that is the problem. With Google every "share" allocated to a nofollow link is then thrown away. Now, does your second page get three shares or one share?
The answer to that probably varies between search engines. Personally I would assume the worst case, which is that one share is passed and the other two shares are discarded. Forget PR sculpting, build your navigation in a way that makes sense for visitors.