SOLUTION: The amount of a radioactive tracer remaining after t days is given by A = A0 e^–0.18t, where A0 is the starting amount at the beginning of the time period. How much should be acq

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Question 7628: The amount of a radioactive tracer remaining after t days is given
by A = A0 e^–0.18t, where A0 is the starting amount at the beginning of
the time period. How much should be acquired now to have 40
grams remaining after 3 days?
Answer by prince_abubu(198) About Me  (Show Source):
You can put this solution on YOUR website!
So the A-final will be 40 grams, right, and you want to know how much you started with 3 days ago? Let's see:

+40+=+A%5B0%5De%5E%28-0.18%283%29%29+

+40+=+A%5B0%5De%5E%28-0.54%29+ <---- simplified.

+%2840%2Fe%5E%28-0.54%29%29+=+A%5B0%5D+ <---- divide both sides by +e%5E%28-0.54%29+.

+68.64+=+A%5B0%5D+ <---- Calculate using calculator. You should get approximately 68.64 grams three days ago.

Calculators differ a lot when it comes to how to punch buttons to compute "e to the something" power, so I can't really explain this part to you.