as sturat said, only google knows that best.
it all depends on the quality of the backlinks + the number of outbound links on those pages
Printable View
One of my sites, a blog, got a PR 3 on the basis (as far as I can see) of a single reciprocal link to a site with related content. The other site's link to me was deep in the content of a page, and my link to it was on my home page.