Question

Suppose that the world's current oil reserves is R= 1830 billion barrels. If, on average, the total reserves is decreasing by 20 billion barrels of oil each year, answer the following:

Answer 1

We have the following information;

The world's current oil reserves is R= 1830 billion barrels and is decreasing by 20 billion barrels of oil a year.

a. We want to give an equation for the remaining barrels R in terms of time t.

The equation is ;

$R=1830-20t\text{ Where R is in billions of barrels}$

b. 8 years from now, the world's oil reserve would be;

$\begin{gathered} R=1830-20(8) \\ R=1670 \end{gathered}$

c. If no other sources are discovered, the world's oil will be finished when R is zero.

Thus;

$\begin{gathered} 0=1830-20t \\ t=91.50\text{ years} \end{gathered}$