Decay problem

[Steven G]

I think that I am missing something here.
Let R(t)= 50e^-0.015tamount that remains after t years.
Now R(200)-R(300)= amount lost during the 2nd hundred years So I would assume that R(200) - (R(200)-R(300)) = R(300) would be the amount not lost. So the answer would be whatever R(300)/100 works out to. My concern is that R(300) is what remains after 300 and this is not what is being ask. Please help.

 

[Dr.Peterson]

The second hundred years would be from t = 100 to 200. The wording is funny, but I would say that the total amount not lost during that time would be what remains, R(200). On the other hand, I suppose the amount not lost during any given year would be what remains after that year, R(t), so you want to find the average of R(101), R(102), ..., R(200).

I'm not at all sure what it really means, though.

 

[Otis]

My answer is 0.0249 lb/yr.

That's the amount not lost during the second hundred years divided by 100 years.

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