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September 22, 2014

September 22, 2014

Posted by **Sam** on Tuesday, September 10, 2013 at 8:36pm.

amount is 133 grams. How long will it be until only 40 % remains?

- Math, science -
**Reiny**, Wednesday, September 11, 2013 at 7:38am1(1/2)^(t/12) = .4

2^(-t/12) = .4

take log of both sides

(-t/12) log 2= log .4

t = -12 log .4/log2 = appr. 15.9 years.

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