10-15 hubs with reasonably good quality and good traffic can help you in getting Adsense approval. Also Google has changed its Google Adsense approval policy effective Aug 31, you might want to check it.
Though fundamentally it didn't change anything, the approval process is now two steps. You apply after enhancing your content - you should not face any problem.
daveenmidtown - Of late Google is strict in giving Adsense approval - so just a blog site with few blogs, and six month ownership may not get Adsense approval these days. Google is verifying each site for "substantial original content" - so applying with enhanced HubPages content might be the best bet to get approval quickly.