### Home > CCA2 > Chapter B > Lesson B.1.4 > ProblemB-46

B-46.

Assume that a DVD loses $60\%$ of its value every year it is in a video store. Suppose the initial value of the DVD was $\80$. .

1. What multiplier would you use to calculate the video’s new values?

$0.40$

2. What is the value of the DVD after one year? After four years?

The DVD will be worth $32$ after one year and $2.05$ after four years.

3. Write a continuous function, $V(t)$, to model the value of a DVD after $t$ years.

$V(t) = 80(0.4)^t$

4. When does the video have no value?

When does $V(t) = (0)$? Is this consistent with reality?

5. Sketch a graph of this function. Be sure to scale and label the axes.

Complete the table in the eTool below to graph the function.
Click the link at right for the full version of the eTool: CCA2 B-46 HW eTool