Question 289033
If model is of the form  {{{p=ae^(-kt)}}}
then for the given half-life
{{{1/2=1*e^(-k*5730)}}}
{{{ln(1/2)=-5730*k}}}

{{{k=(ln(1/2))/(-5730)}}}

{{{k=0.000121}}}


To use the formula and the other given information
{{{p=3*e^(-0.000121*1000)}}}

{{{p=3*e^(-0.121)}}}

{{{p=(0.886)(3)}}}

{{{highlight(p=2.66)}}}