Niko would need 9 marshmallows and 6 graham crackers to make 3 s’mores.
EXPLANATIONN: Ok so to find how many marshmallows he uses for one smore divide 12 by 4, and you get 3, so he uses 3 marshmallows in one smore. Next, we find how much graham crackers he uses in 1 smore by dividing 8 by 4 which is 2 (obvisously but whatever). So now we know that he used 3 marshmallows and 2 graham crackers to make 1 smore, but now we need to know how much of those he needs for 3 graham crackers. So 3 times 3 is 9 so he uses 9 marshmallows, and 2 times 3 is 6 so he uses 6 crackers. Multiply by three cause youre trying to figure out how much stuff he uses for smores. the end, also its a pretty simple problem, just kinda has a long explanation-ish i gues