Google AdSense have some strict account approval policies, and one of them is blog should be six months old and also should have enough content. The recoommended content is about 30 to 35 well written articles if you want to get google adsense approval on blogspot website.
The main question – whether blogspot blogs are ever accepted, or if you can be approved to adsense while using a blogger free hosting and a custom domain. The answer to this is yes, you will be approved to adsense with a blogspot domain even without a custom domain and also you can get approval with a custom domain on free blogger hosting by google.
There is a simple trick which you can use to get your AdSense account approved for Blogspot domain quickly. Mostly, the main thing Google adsense needs is content, and this must be unique content. If your BlogSpot account have a sufficient number of post (minimum 20+) then this will be easy to get your AdSense account approved. Also, something else i can tell you is that If you have personal domain and host chances of AdSense approval are very high.