Whick one of these isnt like the other? 25,16,49,63,81

16 isnt like the others because all of the other numbers are high and 16 is low.

16 is different because it's the only even number. 

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