Questions: The owner of a photocopy store charges 8 cents per copy for the first 100 copies and 6 cents per copy for each copy exceeding 100. In addition, there is a setup fee of 2.60 for each photocopying job.
(a) Determine R(x), the revenue from doing one photocopying job consisting of x copies.
(b) If it costs the store owner 4 cents per copy, what is the profit from doing one photocopying job consisting of x copies? (Recall that profit is revenue minus cost.)
(a) Choose the correct answer below.
A. R(x)=.08x+2.60 for 1≤x≤100 .06x for 100<x
B. R(x)=.08x+2.60 for 1≤x≤100 .06x+2.60 for 100<x
C. R(x)=.08x+2.60 for 1≤x≤100 .14x+2.60 for 100<x
D. R(x)=.08x+2.60 for 1≤x≤100 .06x+4.60 for 100<x
Transcript text: The owner of a photocopy store charges 8 cents per copy for the first 100 copies and 6 cents per copy for each copy exceeding 100 . In addition, there is a setup fee of $\$ 2.60$ for each photocopying job.
(a) Determine $\mathrm{R}(\mathrm{x})$, the revenue from doing one photocopying job consisting of x copies.
(b) If it costs the store owner 4 cents per copy, what is the profit from doing one photocopying job consisting of x copies? (Recall that profit is revenue minus cost.)
(a) Choose the correct answer below.
A. $R(x)=\left\{\begin{array}{ll}.08 x+2.60 & 1 \leq x \leq 100 \\ .06 x & 100
Solution
Solution Steps
Step 1: Understand the pricing structure
The revenue \( R(x) \) depends on the number of copies \( x \). For the first 100 copies, the charge is 8 cents per copy plus a setup fee of \$2.60. For each copy exceeding 100, the charge is 6 cents per copy plus the same setup fee.
Step 2: Write the revenue function for \( 1 \leq x \leq 100 \)
For \( 1 \leq x \leq 100 \), the revenue is calculated as:
\[
R(x) = 0.08x + 2.60
\]
This includes the cost per copy (8 cents) and the setup fee (\$2.60).
Step 3: Write the revenue function for \( x > 100 \)
For \( x > 100 \), the revenue is calculated as:
\[
R(x) = 0.08 \times 100 + 0.06(x - 100) + 2.60
\]
Simplify the expression:
\[
R(x) = 8 + 0.06x - 6 + 2.60 = 0.06x + 4.60
\]
Step 4: Compare with the given options
The correct revenue function is:
\[
R(x) = \begin{cases}
0.08x + 2.60 & \text{if } 1 \leq x \leq 100 \\
0.06x + 4.60 & \text{if } x > 100
\end{cases}
\]
This matches option D.
Step 1: Understand the profit calculation
Profit is calculated as revenue minus cost. The cost per copy is 4 cents, so the total cost for \( x \) copies is \( 0.04x \).
Step 2: Write the profit function for \( 1 \leq x \leq 100 \)
For \( 1 \leq x \leq 100 \), the profit is:
\[
P(x) = R(x) - \text{Cost} = (0.08x + 2.60) - 0.04x = 0.04x + 2.60
\]
Step 3: Write the profit function for \( x > 100 \)
For \( x > 100 \), the profit is:
\[
P(x) = R(x) - \text{Cost} = (0.06x + 4.60) - 0.04x = 0.02x + 4.60
\]
Step 1: Identify the correct revenue function
From part (a), the correct revenue function is option D:
\[
R(x) = \begin{cases}
0.08x + 2.60 & \text{if } 1 \leq x \leq 100 \\
0.06x + 4.60 & \text{if } x > 100
\end{cases}
\]
Final Answer
(a) The correct answer is D.
(b) Profit for \( 1 \leq x \leq 100 \) is \( P(x) = 0.04x + 2.60 \) and for \( x > 100 \) is \( P(x) = 0.02x + 4.60 \).