Question 1202994
{{{A=ae^(-0.0099x)}}}  to make the text symbols easier to manage


According to question, .....,  {{{0.3=1*e^(-0.0099x)}}} and you want to solve for x.



{{{ln(0.3)=ln(e^(-0.0099x))}}}

{{{ln(0.3)=-0.0099x*ln(e)}}}

{{{ln(0.3)=-0.0099x*1}}}

{{{x=ln(0.3)/(-0.0099)}}}---------and you can finish computing this...