Question

which is the better buy?
4-pack of batteries for $9.80
5-pack of batteries for $12.30
submit

Explanation:

Step1: Calculate unit price for 4 - pack

To find the unit price (price per battery) for the 4 - pack, we divide the total price by the number of batteries. The formula for unit price $p$ is $p=\frac{\text{Total Price}}{\text{Number of Batteries}}$. For the 4 - pack, total price is $\$9.80$ and number of batteries is 4. So, $p_1=\frac{9.80}{4}=2.45$ dollars per battery.

Step2: Calculate unit price for 5 - pack

For the 5 - pack, total price is $\$12.30$ and number of batteries is 5. Using the same unit price formula, $p_2 = \frac{12.30}{5}=2.46$ dollars per battery.

Step3: Compare unit prices

Now we compare $p_1 = 2.45$ and $p_2=2.46$. Since $2.45<2.46$, the 4 - pack has a lower unit price.

Answer:

4 - pack of batteries for $\$9.80$