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| Question 145094:  Could someone please help me on two logarithm word problems?
 1)Recall that A = Ao2(-t/h). If the half-life of a substance is 10 years, how much of a 400 - gram sample will remain in 20 years?
 2)Recall that A = Ao2 (-t/h). If the half-life of a substance is 4 days, how much of a 320-gram sample will remain in 6 days?
 Thank you in advance for all the time all of you put into helping people like me.
 Sincerely,
 Elle J.
 Answer by stanbon(75887)
      (Show Source): 
You can put this solution on YOUR website! 1)Recall that A(t) = Ao2(-t/h). If the half-life of a substance is 10 years, how much of a 400 - gram sample will remain in 20 years? ----------
 A(20) = 400* 2^(-20/10)
 A(20) = 400* 2^-2
 A(20) = 400* 1/4
 A(20) = 100 grams
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 2)Recall that A = Ao2 (-t/h). If the half-life of a substance is 4 days, how much of a 320-gram sample will remain in 6 days?
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 A(6) = 320 *2^(-6/4)
 A(6) = 320 *2^(-3/2)
 A(6) = 320 *(0.35355...)
 A(6) = 113.137... grams
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 Cheers,
 Stan H.
 
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