Let's break down the cost of Vera's purchase in detail:
1. Cost of each type of print:
- For the 3 prints of [tex]$5 \times 7$[/tex] at [tex]$0.89 each:
\[ 3 \times 0.89 = 2.67 \, \text{dollars} \]
- For the 12 prints of $[/tex]4 \times 6[tex]$ at $[/tex]0.15 each:
[tex]\[ 12 \times 0.15 = 1.80 \, \text{dollars} \][/tex]
- For the 1 print of [tex]$8 \times 10$[/tex] at [tex]$2.99:
\[ 1 \times 2.99 = 2.99 \, \text{dollars} \]
2. Cost of the photo album:
\[ 8.69 \, \text{dollars} \]
3. Subtotal (sum of all items purchased):
\[ 2.67 + 1.80 + 2.99 + 8.69 = 16.15 \, \text{dollars} \]
4. Tax calculation (7% of the subtotal):
\[ 16.15 \times 0.07 = 1.1305 \approx 1.13 \, \text{dollars} \]
5. Total before shipping (subtotal + tax):
\[ 16.15 + 1.13 = 17.28 \, \text{dollars} \]
6. Shipping charges based on the table:
- Since Vera's total before shipping is $[/tex]17.28, which is less than [tex]$20, she qualifies for free standard shipping.
7. Final total cost (total before shipping + shipping):
\[ 17.28 + 0 = 17.28 \, \text{dollars} \]
Given that Vera was billed $[/tex]20.78:
[tex]\[ \text{Billed amount} - \text{Calculated amount} = 20.78 - 17.28 = 3.50 \, \text{dollars} \][/tex]
Thus, Vera has been overcharged by [tex]$3.50.
Therefore, the best answer is:
d. Vera has been overcharged by $[/tex]3.50 for her purchase.
