Ok, some practical math:

Originally posted by Bishopcrw
Also the question fails to address the compounding effect of inflation.
Inflation is not calculated at the original base year but the preceeding year which already has infaltion in it.

This results in the 5% inflation doubling the cost in 15.5 years, not 20.

Isn't the cost actually doubled in 14 years?

Originally posted by Balla88
Isn't the cost actually doubled in 14 years?

Rule of thumb for compound interest (useful for approximations) is 72/percentage = number of periods it takes to double. To get the actual answer find x such that:

1.05^x = 2

Using log rules we get 14.207 years. So 14.4 years (via the approximation) isn't a bad guess.

I thought that the Rule of 70 is more generally accepted than 72. Not that there's much difference. An example that deals directly with a 5% increase:

http://www.mhhe.com/economics/mcconnell15e/graphics/mcconnell15eco/common/dothemath/ruleof70.html

Hmmm, well for a start energy prices globally are on the rise! Secondly it would cost you more to freeze just 1 steak, freezers are more efficient if they are full. Also air temperature will have a marked effect. Finally you can only freeze food for a limited time, beef i believe is up to a year.

Sorry!


Matty x

Two more things.....If you decide to eat the steak how much will it cost you to cook it, price of cooker, electricity/gas, purchase of pan to cook it in etc. and how much kj of energy will you use working this all out, kj of energy in bodily movement to cook it, shoe leather to walk to the cooker etc; and how much energy will you obtain from the steak!?

Far too complicated!!

matty x

Originally posted by mwillerton
Two more things.....If you decide to eat the steak how much will it cost you to cook it, price of cooker, electricity/gas, purchase of pan to cook it in etc. and how much kj of energy will you use working this all out, kj of energy in bodily movement to cook it, shoe leather to walk to the cooker etc; and how much energy will you obtain from the steak!?

Far too complicated!!

matty x

I think that goes a bit beyond the original question, which was only
hypothetical anyway. We already mentioned freezers don't just
freeze one steak. BTW, there were cans of food found in Antarctica
which had been frozen there by the weather for over 50 years
and found to be edible. I don't think the temps there got much
above minus 30, so the lifetime of frozen food depends a lot on
just how cold its stored at.

Originally posted by Balla88
Isn't the cost actually doubled in 14 years?

Actually it depends on your calc!

Your calculation differs from mine in that I excluded the first year for inflation as this was the base year of costs. Inflation is then calculated for each year following.

Originally posted by mwillerton
Hmmm, well for a start energy prices globally are on the rise! Secondly it would cost you more to freeze just 1 steak, freezers are more efficient if they are full. Also air temperature will have a marked effect. Finally you can only freeze food for a limited time, beef i believe is up to a year.

Sorry!


Matty x

I was thinking of what you would want such a long term storage for
besides food, I thought what about time vaults for dna?
Suppose we have a situation where mutations occur for whatever
reason, say an influx of cosmic rays or neutrinos which cause
unwanted mutations maybe not even in humans but in our food
sources, they may want to save dna strands which would be a recording
of the correct sequence against which to compare mutations, say
one hundred years later. Long term freezing may have a use then.
Even now we freeze sperm samples, but I don't think they are
designed for the hundred year time frame. I think some
DNA has been analyzed to have at least SOME code left even in
the soft centers of Dinosaurs and for sure in Mastadons, not
complete though but that was only natural storage.