Question

The total reserves of a non-renewable resource are 400 million tons. Annual consumption is 25 million tons per year and increases at 1% per year. After how many years will reserves be exhausted?

Answer 1

Please help!!! I've been working on this for hours and I still can't understand it..

Answer 2

The answer is apparently 14.916 years
I don't know why?

Answer 3

@deepa.banapur as per i can get it has smthing to do with GP.. let me see if i can hellp

Answer 4

oh my goodness thank you so much
it's on the chapter about geometric infinite/finite series

Answer 5

@hartnn I believe you could be of assistance

Answer 6

4 Years

Answer 7

@hba @ganeshie8 @jagatuba

Answer 8

it'll expire in 4 years without the 1% interest. So you must figure out how long it'll will take them to use 4% of 25 million and subtract that from 4 years.

Answer 9

Hi Kales, but the answer is apparently 14.916.. How did you get 4?

Answer 10

I am so confused

Answer 11

14 years?
I got the answer by simply dividing 400 by 25, wait omg, i read the question wrong.
Yes 14.916 is correct

Answer 12

because with out teh 1% interest it would take 16 years to use up the resources.

Answer 13

how did you get that?
So far, I got the the geometric series : \[400-25(0.01)^{n}\]
But that's it..

Answer 14

I used simple algebra to figure out the 16 years at first, 400 divided by 25, but in order to get 14.9... you must add up the one percent interest of each year, the using the information given, (they consume 25 million tons per year) Figure out how long it would take them to consume the 1% interest and then subtract that from 16. It's a bit complicated but i think your formula is correct. Double check to make sure

Answer 15

*1% interests added up