StrathmoreArtist Trading Cards 2.5"X3.5" 5/Pkg-Illustration Board Vellum -62105907, White

Is there 5 cards or 20 cards?

Has anyone used Copic Markers with these? It says dry media, but then doesn't state what kind

This ad clearly states that it is for 5 sheets and that 5 sheets make 20 cards. Is that true with this specific purchase or is it a lie?

This is "trading card cardstock? Can you print on from a printer?