Calculate the percentage growth for a county with a population of 6 million in a year in which it had 100,000 births, 70,000 deaths, 30,000 immigrants and 40,000 emigrants

Country's population = 6 million

The percentage growth rate = (10,000/6,000,000) * 100 = 0.166666666667%

2. Reduction in concentration = 65 ppm - 7 ppm = 58 ppm

Percentage change = (58 ppm / 65 ppm) * 100 = 89.23% then again i may be wrong