Answer:
<em>C(12)=$570.18</em>
<em>C(20)=$57.08</em>
Step-by-step explanation:
<u>Exponential Decay Function</u>
The exponential function is often used to model natural growing or decaying processes, where the change is proportional to the actual quantity.
An exponential decaying function is expressed as:

Where:
C(t) is the actual value of the function at time t
Co is the initial value of C at t=0
r is the decaying rate, expressed in decimal
The depreciation of goods is often modeled as an exponential function. The new car costs $18,000 and its price depreciates at r=25%= 0.25 every year.
The depreciation model is:

Operating:

At t=12 years, the price will be:

C(12)=$570.18
At t=20 years, the price will be:

C(20)=$57.08
3/4 ÷ 4/5 =
3/4 times 5/4 =
15/16 = .9375
8 7/10 as a improper fraction is 87/10
Answer:
Rate of interest r = 2.83 % (Approx.)
Step-by-step explanation:
Given:
Amount invested p = $2,600
Amount get A = $4,300
Number of year n = 18
Find:
Rate of interest r
Computation:
A = p(1+r)ⁿ
4,300 = 2,600(1+r)¹⁸
(1+r)¹⁸ = 1.653846
Rate of interest r = 2.83 % (Approx.)