Given:
The value of car before two years = £10000
The value of the car decreases by 5% each year.
To find:
The present value of the car.
Solution:
The exponential decay model for present value is
![y=a\left(1-(r)/(100)\right)^t](https://img.qammunity.org/2022/formulas/mathematics/high-school/qt93ak28j2dkvn27x2ucx5ymqh9b1ug5z3.png)
Where, a is the initial value, r is the rate of decay and t is time in years.
Putting P=10000, r=5 and t 2, we get
![y=10000\left(1-(5)/(100)\right)^2](https://img.qammunity.org/2022/formulas/mathematics/high-school/934pmowvop5demexnuc30jtidkm9ae426f.png)
![y=10000\left(1-0.05\right)^2](https://img.qammunity.org/2022/formulas/mathematics/high-school/5jmdvhfpisyam8n02wrk8px7fxdpihgpua.png)
![y=10000\left(0.95\right)^2](https://img.qammunity.org/2022/formulas/mathematics/high-school/pduvtwyt0376zru76a3dezmzvafnfazb2f.png)
On further simplification, we get
![y=10000(0.95)(0.95)](https://img.qammunity.org/2022/formulas/mathematics/high-school/c767b5l4cigh1pd2rud0a8rkqbuetexx4g.png)
![y=9025](https://img.qammunity.org/2022/formulas/mathematics/high-school/sne88k5lbcckssyhgmf8y41t303g7u3u7x.png)
Therefore, the present value of the car is £9025.