Raid 10: 2X 500GB + 1x 1TB

I have a 500GB HDD and am considering buying a second one to run them in Raid 0 however for the safety of my data I thought it would be better to create a RAID 10 array.

My question is can I create a Raid 10 array with the 2 500GB HDDs performing data stripping and a single 1TB HDD to mirror the two 500GB HDDs.

Isn't the minimum for a RAID 10 array 4 drives?

You need x4 drives that are the same size however you can do raid 5 with x3 discsĀ 

http://www.cyberciti.biz/tips/raid5-vs-raid-10-safety-performance.html

http://en.wikipedia.org/wiki/RAID

But you said that you were doing a RAID 10...