Question 236622
This is a logarithmic equation not really understanding this.

A woman deposits $50,000 in a savings account with 4% continuously compounded interest. How many years must she wait until the balance has doubled.
<pre><font size = 4 color = "indigo"><b>
{{{A=Pe^(rt)}}}

{{{P=50000}}}
{{{A= 2P = 100000}}}
{{{r=.04}}}

{{{2P=Pe^(0.04t)}}}

Divide both sides by {{{P}}}

{{{2=e^(0.04t)}}}

Use the rule:  {{{A=e^B}}} is equivalent to {{{ln(A)=B}}}

{{{ln(2)=0.04t}}}

Divide both sides by {{{0.04}}}

{{{ln(2)/0.04=(0.04t)/0.04}}}

{{{17.32867951=t}}}

about 17 years, 4 months.

Edwin</pre>