Answer :
[tex] \frac{70}{1,8} \approx 38.8 \ \ \ \ \ \rightarrow \ the \ amount \ of \ time \ to \ double \ the \ consumption \\ \\
38,8 - 100\% \\ 6 - x \\
38,8 x = 600\% \\x \approx 15.5\% \\ \\
In \ six \ years \ oil \ consumption \ will \ increase \ by \ approximately \ 15.5\%[/tex]