You are going to order some blank recordable DVD discs. The shipping for your entire order will be [tex]$\$[/tex]5.99[tex]$, and the discs come in 100 packs which sell for $[/tex]\[tex]$33$[/tex].

(a) Letting [tex]\( n \)[/tex] represent the number of 100 packs purchased, write a function [tex]\( C(n) \)[/tex] that represents the average cost per disc for your order. Be sure to include the shipping charge in your cost calculations.

[tex]\[ C(n) = \boxed{} \][/tex]

(b) Using the function you found in part (a), write an equation to determine the minimum number of 100 packs that must be purchased in order that the average cost per disc is equal to [tex]$\$[/tex]0.3317[tex]$.

\[ \boxed{} \]

(c) Determine the minimum number of 100 packs that must be purchased in order that the average cost per disc is less than $[/tex]\[tex]$0.3317$[/tex].

[tex]\[ \boxed{} \][/tex]



Answer :

Let's solve the given problem step-by-step:

### Part (a)
To find the average cost per disc, we need to include both the cost of the discs and the shipping charge.

1. Cost of discs: If each 100-pack costs \[tex]$33 and you purchase \( n \) packs, the total cost for the discs would be \( 33 \cdot n \) dollars. 2. Shipping charge: The shipping cost is a flat fee of \$[/tex]5.99 regardless of the number of packs ordered.

So, the total cost for [tex]\( n \)[/tex] 100-packs is:
[tex]\[ \text{Total cost} = 33n + 5.99 \][/tex]

Given that each 100-pack contains 100 discs, [tex]\( n \)[/tex] packs will contain [tex]\( 100n \)[/tex] discs. Thus, the average cost per disc is:
[tex]\[ C(n) = \frac{\text{Total cost}}{\text{Number of discs}} = \frac{33n + 5.99}{100n} \][/tex]

Therefore, the function [tex]\( C(n) \)[/tex] that represents the average cost per disc for your order is:
[tex]\[ C(n) = \frac{33n + 5.99}{100n} \][/tex]

### Part (b)
Next, we need to determine the minimum number of 100-packs that must be purchased for the average cost per disc to be equal to \[tex]$0.3317. We set up the equation by equating the cost per disc function \( C(n) \) to 0.3317: \[ \frac{33n + 5.99}{100n} = 0.3317 \] To solve for \( n \), we clear the fraction by multiplying both sides by \( 100n \): \[ 33n + 5.99 = 0.3317 \cdot 100n \] \[ 33n + 5.99 = 33.17n \] Next, isolate \( n \) by subtracting \( 33n \) from both sides: \[ 5.99 = 33.17n - 33n \] \[ 5.99 = 0.17n \] Finally, solve for \( n \): \[ n = \frac{5.99}{0.17} \approx 35.2352941176471 \] ### Part (c) We need to determine the minimum number of 100 packs such that the average cost per disc is less than \$[/tex]0.3317. From part (b), we found that [tex]\( n = 35.2352941176471 \)[/tex] packs is needed for the average cost to be exactly \[tex]$0.3317. Since \( n \) must be an integer and we want the average cost to be less than \$[/tex]0.3317, we round [tex]\( n \)[/tex] up to the next whole number:
[tex]\[ \text{Minimum number of 100 packs} = 36 \][/tex]

Thus, the minimum number of 100 packs that must be purchased for the average cost per disc to be less than \$0.3317 is [tex]\( \boxed{36} \)[/tex].