8x12 Contact Sheet with one sigle image in various format

Hello Sir,

I would to understand how I can realise a 8x12 contact sheet displaying the same image in various formats ?

It is commonly used in school photography.

One image would be 13x18cm, 2 others 6x9cm, and the 6 thumbnails showing the same portrait.

I am a european photographer so I do not know perfectly the corresponding sizes, should be :

1x   5x7

2x   2x3.5

I do not get the methodology.

I can show you some various examples... such as this one !

http://www.photomathieu.com/

Thanks for your help ! Urgent !!