[Typhus]

What are the chemical formulas for Tin (II) Carbide and Tin (IV) Carbide?

I had thought Tin (IV) Carbide was SnC
and Tin (II) Carbide was Sn2C
however I was marked wrong on a test and cant seem to find the formulas online anywhere.

[baboom]

that was a trick question:

This is what I found from wikipedia:

Some metals, such as lead and tin, are believed not to form carbides under any circumstances. There exists however a mixed titanium-tin carbide, which is a two-dimensional conductor.[6] (In 2007 there were two reports of a lead carbide PbC2, apparently of the acetylide type; but these claims have yet to be published in reviewed journals.)

[Typhus]

Actually its not a trick question

I need a theoretical formula for each of those two compounds.

[AWK]

It seems only SnC is known (though not referred in wikipedia)
http://www.americanelements.com/snc.html

From a formal point of view Sn₂C is a formula of tin(II) carbide.
Other formal formulas: SnC₂ for tin(II) acetylenide and Sn₂C₃ for tin(II) sesquicarbide but all these three compounds are not known so far.