Answer:
A. 38%
Explanation:
Percentage increase = (Increase/original value)×100
P.I.C= (ΔC/C₁)×100 .................. Equation 1
Where P.I.C = Percentage increase in the concentration of carbon dioxide from 1790 to 2007, ΔC = increase in the concentration of carbon dioxide from 1790 to 2007,
C₁ = concentration of carbon dioxide in 1790.
But,
ΔC = C₂ - C₁............................. Equation 2
Substituting equation 2 into equation 1.
P.I.C = [(C₂ - C₁)/C₁]×100.................... Equation 2
Given: C₁ = 278 ppm, C₂ = 383 ppm
Substituting into equation 2
P.I.C = [(383-278)/278]×100
P.I.C = (105/278)×100
P.I.C = 37.77%
P.I.C ≈ 38%
The right option is A. 38%