The world's total petroleum reserve is estimated at 2.0 x 10^22 joules la joule (j) is the unit of energy where 1j =1kg m^2/s^2). at the present rate of consumption, 1.8 x 10^20 joules per year (j/yr), how long would it take to exhaust the supply?

It will take 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, joules of petroleum are being consumed per year.

Hence, applying unitary method, joules of petroleum can be consumed in

h

10 years is the answer