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July 25, 2014

July 25, 2014

Posted by **Monica** on Monday, June 13, 2011 at 10:40pm.

- math/algebra -
**Reiny**, Monday, June 13, 2011 at 10:47pm30 = 40e^10k

.75 = e^10k

10k = ln.75

k = ln.75/10 = -.028768

then

1/2 = e^-.028768t

- .028768t = ln .5

t = ln .5/-.028768 = 24.09

the half-life is appr. 24.1 hours

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