Answer:
It will take [tex]1.1\times 10^{2}years[/tex] to exhaust the supply
Explanation:
We have to apply unitary method to solve this problem.
Divide total petroleum reserve by petroleum consumption in each year to calculate estimated time.
Presently, [tex]1.8\times 10^{20}[/tex] joules of petroleum are being consumed per year.
Hence, applying unitary method, [tex]2.0\times 10^{22}[/tex] joules of petroleum can be consumed in [tex]\frac{2.0\times 10^{22}}{1.8\times 10^{20}}years=1.1\times 10^{2}years[/tex]
