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

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



On further simplification, we get


Therefore, the present value of the car is £9025.