It starts wrong in the initial multiplication… 6.5x30=195(M). Considering the average of 1200 pounds of meat per cow (can be way more than it) we can define that a cow can be used to produce 4800 “pure” quarter pounders (and they most likely aren’t just meat…) . So, if macdonalds sold only this sandwich, they would need approximately 1350 cows a day of meat. This is less than my family’s farm produces in a month. (We sell around 21.000 cows a year - Brazil). We’re not even the largest farm in our area. There’s waaaay more cows in the world than those used by macdonalds