SOLUTION: Suppose that the world's current oil reserves in billions of barrels is given by the equation R(t)=-21t+1960 where t represents the number of years since now. 8 years from now,

Question 810821: Suppose that the world's current oil reserves in billions of barrels is given by the equation R(t)=-21t+1960 where t represents the number of years since now.
8 years from now, the total oil reserves will be billions of barrels.
If no other oil is deposited into the reserves, the world's oil reserves will be completely depleted approximately years from now.
Round your answer to the nearest year.

my question here is how do I start it. Most of my homework problems are similiar to this but I cannot remember how to start it.
Thanks you so much in advance!!! Natisha
Found 2 solutions by stanbon, Charles3475:
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
Suppose that the world's current oil reserves in billions of barrels is given by the equation R(t)= -21t+1960 where t represents the number of years since now.
8 years from now, the total oil reserves will be ? billions of barrels.
If no other oil is deposited into the reserves, the world's oil reserves will be completely depleted approximately ? years from now.
Round your answer to the nearest year.

Answer by Charles3475(23) (Show Source): You can put this solution on YOUR website!
You want to know when the the reserves will be completely depleted.
This is the same as asking when R(t) is equal to zero.
At t=0; R(0) = -21(0) + 1960 = 1960 billion barrels
Each year 21 billion barrels are consumed.
As stated previously, the reserves are fully depleted (consumed) when R(t) = 0
So R(t) = 0 = -21t + 1960 when the reserves are gone.
0= -21t + 1960
Adding 21t to both sides
21t = 1960
Divide both sides by 21
t = 93.33 years
RELATED QUESTIONS
Suppose that the world's current oil reserves is 2020 billion barrels. If, on average,... (answered by josmiceli)
P(t)=6.5e^.014t, where t=0 is 1960 and the population is in billions of people.... (answered by ewatrrr,richwmiller)
The total amount spent in the US for wireless communications S in billions of dollars is... (answered by josmiceli)
the expenditure,E(t), in billions of dollars, by oil companies for new oil and natural... (answered by sanjay_sp008)
Oil is pumped from an oil field at a constant rate each year, so that its oil reserves... (answered by Theo)
The total world consumption of oil increased from 68.200 million barrels per day in 1995... (answered by ankor@dixie-net.com)
Hi thank you for your time! Here is the problem I am working on. WIll you show me how you (answered by nerdybill)
In an oil field, as more wells are drilled each oil well pumps less oil; however, the... (answered by ankor@dixie-net.com)
If p represents the world population in billiond and y represent the number of years... (answered by josmiceli,MathLover1)