We have been given that last month Maria purchased a new cell phone for $500. The store manager told her that her cell phone would depreciate by 70% every 6 months.
We know that an exponential function is in form , where,
y = Final value,
a = Initial value,
r = Decay rate in decimal form,
x = Time in years.
Let us convert into decimal form.
Initial value of car is 500, so .
Since value of phone depreciates every months, so value of phone will depreciate twice in a year.
Upon substituting our given values in exponential decay function, we will get:
To find the value of phone after 2 years, we will substitute in our equation.
Therefore, option D is the correct choice.
Let us simplify our equation.
Therefore, option B is correct as well.
