Respuesta :
The age of the car that Devon purchased is given by: Option C: 5 years
How to calculate compound interest's amount?
If the initial amount (also called as principal amount) is P, and the interest rate is R% per unit time, and it is left for T unit of time for that compound interest, then the interest amount earned is given by:
[tex]CI = P(1 +\dfrac{R}{100})^T - P[/tex]
The final amount becomes:
[tex]A = CI + P\\A = P(1 +\dfrac{R}{100})^T[/tex]
We can use compound interest's formula (with a bit modification if necessary) whenever there is compounding on a base amount on some fixed rate for some time.
For this case, there is decrement happening, so rate can be taken negative. Thus, we take:
R = -35%
Let the car is T years old.
Then, as we have: Initial price of the car = P = $16000, and the final price of the car = A = $2000, thus, we get:
[tex]A = P(1 +\dfrac{R}{100})^T\\\\2000 = 16000(1 + (-35/100) )^T\\1/8 = (1-0.35)^T\\0.125 = 0.65^T\\\\T = log_{0.65}(0.125)\\T \approx 4.827 \approx 5 \text{ (in years) }[/tex]
Thus, the age of the car that Devon purchased is given by: Option C: 5 years
Learn more about compound interest here:
https://brainly.com/question/11897800
