Number of faces + (Number of vertices - Number of edges) = 2 So plugging in the numbers it would then be 18+(12-30)=2 18-18=2 0=2 Kelvin would be wrong and I disagree with him. (Because ...*plugin work cited above*)
The answer would be 1 million because if the average person lives to be 70 multiply that by 2000 and you get 51100000 so I would say that total is closer to 1 million then it is to 3 billion