My answer is 82. I added up 90 + 80 + 75 = 245. I then divided that by 3 because there are 3 different cultures. And the number was 81. something. So, I rounded and got 82. But I'm not sure if that's the right answer.
75 people because if shrink it to 20 and multiply your results be 5 then only 10 Wouldn't have any heritage. Another ten with Native American or English heritage and only 5 people with Native American so Add that up its 25 people out of 100 it's 75 left.
