If $48,000 is invested in an account earning 3.1% interest compounded continuously, determine how long it will
take the money to triple. Round to the nearest year. Use the model A = Pert where A represents the future value
of P dollars invested at an interest rate r compounded continuously for t years.

Respuesta :

Answer:

It will take about 35.439  years to triple.

Step-by-step explanation:

Recall the formula for continuously compounded interest:

[tex]A=P\,e^{r*t}[/tex]

where "A" is the total (accrued or future) accumulated value, "r" is the rate (in our case 0.031 which is the decimal form of 3.1%), "P" is the principal, and "t" is the time in years (our unknown).

Notice also that even that the final amount we want to get is three times $48,000. So our formula becomes:

[tex]3\,*\,48,000=\,48,000\,\,e^{0.031\,*t}\\\frac{3\,*\,48,000}{48,000} =e^{0.031*t}\\3=e^{0.031*t}[/tex]

Now,in order to solve for "t" (which is in the exponent, we use logarithms:

[tex]ln(3)=0.031\,*\,t\\t=\frac{ln(3)}{0.031} \\t=35.439 \,\,years[/tex]