Question : full, incremental, diferential back ups

Could it be possible to mix full back ups, incremental back ups and differential back ps in one back uop and restore strategy.

Answer : full, incremental, diferential back ups

Why couldn't it be possible?  Though I don't think it would prove to be WISE most of the time... I'd suggest you read up on backups - reference:
http://www.lwcomputing.com/tips/static/backup.asp