Respuesta :

Answer:

[tex]t = 15.7[/tex]

Step-by-step explanation:

Given

[tex]Principal = 25000[/tex] --- P

[tex]Amount = 75000[/tex] --- A

[tex]Rate = 7\%[/tex] --- R

Required

Determine the time (t)

Using continuous growth formula:

We have

[tex]A = Pe^{rt}[/tex]

Convert rate to decimal

[tex]Rate = 7\%[/tex]

[tex]r = 0.07[/tex]

Substitute values for A, P and r

[tex]75000 = 25000 * e^{0.07t}[/tex]

Divide both sides by 25000

[tex]3 = e^{0.07t}[/tex]

Rewrite the exponential function as logarithmic, we have:

[tex]ln3 = 0.07t[/tex]

Reorder

[tex]0.07t = ln3[/tex]

Divide both sides by 0.07

[tex]t = \frac{ln3}{0.07}[/tex]

[tex]t = \frac{1.09861228867}{0.07}[/tex]

[tex]t = 15.69[/tex]

[tex]t = 15.7[/tex]

Hence, the time is approximately 15.7 years