Interesting question. Does that mean near the end of humanity?
Solution 1:
10^10 = 1,000,000,000
10^12 = 100,000,000,000
100,000,000,000/1,000,000,000 = 100 trees per person
Solution 2:
10^12 / 10^10 --- 10^10 / 10^10
10^2/1 = 10^2 = 100 trees per person
