The number 21 is what percent of 75

Idrk but i think u should figure out the n dia n then the units it will make it way more easier

Thats where they was ported and the fields that noone really knew much about needed tended, so they put slaves out there do free work and huge profits and so on the north decided to hold its own and was more different way of survival did not have same climate conditions to afford protecting slaves from winter so expenses be diff from south