Question 46769
I will start where you left off:
{{{40=A[0] e^(-0.18t) }}}
{{{t=3}}}
{{{40=A[0] e^(-0.54) }}}
{{{40/(e^(-0.54))=A[0] }}}
{{{A[0] =68.6}}}grams


I hope this helps,
Adam
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