SOLUTION: The half-life of aspirin in a person's bloodstream is about 15 minutes. If a person's bloodstream contains 256 milligram of aspirin, how much of that aspirin will remain after 105

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Question 852386: The half-life of aspirin in a person's bloodstream is about 15 minutes. If a person's bloodstream contains 256 milligram of aspirin, how much of that aspirin will remain after 105 minutes?
Answer by josgarithmetic(39620) About Me  (Show Source):
You can put this solution on YOUR website!
A general model can be y=pe%5E%28-kt%29, y=amount after time t, and p = initial amount, t is time in minutes.

ln%28y%29=ln%28p%29%2B%28-kt%29%2A1
ln%28y%29=ln%28p%29-kt
ln%28y%29-ln%28p%29=-kt
ln%28p%29-ln%28y%29=kt
highlight_green%28kt=ln%28p%29-ln%28y%29%29
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Separately solve for k, and for t.
k=%28ln%28p%29-ln%28y%29%29%2Ft, and use this with the given half-life information to get the k value;
t=%28ln%28p%29-ln%28y%29%29%2Fk, and use this to .... No, you will not need this;
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The more specific model you have now is:
y=256%2Ae%5E%28-kt%29, and you now have the appropriate information formed to get the value of k.




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You should have found k=ln%282%29%2F15=0.0462.