To determine the unit price (price per pencil) in each pack of pencils, we shall use the following;
![\text{Unit price}=\frac{Total\text{ price}}{total\text{ pencils}}](https://img.qammunity.org/2023/formulas/mathematics/college/yquqxnyoqdfydfueurqrhmqfktwfrw3e9e.png)
For brand A, the unit price is;
![\begin{gathered} \text{Unit price}=(3.29)/(12) \\ \text{Unit price}=0.274166 \\ \text{Unit price}\approx0.27\text{ (rounded to the nearest tenth)} \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/qxwpujx2nf89ta2trdpg5arbk3eh717gqt.png)
For brand B, the unit price is;
![\begin{gathered} \text{Unit price}=(8.99)/(28) \\ \text{Unit price}=0.321071 \\ \text{Unit price}\approx0.32 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/up140m4o53owstcszja3vlo9ej28gjvbib.png)
If you decided to buy per unit rather than per pack, then the better option is Brand A which costs $0.27 each.
ANSWER:
Unit price for Brand A = $0.27 for each pencil
Unit price for Brand B = $0.32 for each pencil
The better buy is Brand A