<PRE><B>Question 598645</B>
Iodine-131 is used to find leaks in water pipes. 
It has a half life of 8.14 days. Write the exponential decay function for a 200 mg sample. 
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A(t) = 200*(1/2)^(t/8.14)
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Find the amount of Iodine 131 remaining after 72 days.
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A(72) = 200(1/2)^(72/8.14)
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= 200*0.0022
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= 0.4349 mg
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Cheers,
Stan H.
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