Question

which is the better buy? 3 - ounce bottle of soap for $1.50 9 - ounce bottle of soap for $4.32

Explanation:

Step1: Calculate unit price for 3-ounce

To find the unit price (price per ounce) for the 3-ounce bottle, we divide the total price by the number of ounces. The formula for unit price \( p \) is \( p=\frac{\text{Total Price}}{\text{Ounces}} \). For the 3-ounce bottle, total price is \$1.50 and ounces is 3. So, \( p_{3}=\frac{1.50}{3} = 0.50 \) dollars per ounce.

Step2: Calculate unit price for 9-ounce

For the 9-ounce bottle, total price is \$4.32 and ounces is 9. Using the same unit price formula, \( p_{9}=\frac{4.32}{9}= 0.48 \) dollars per ounce.

Step3: Compare unit prices

Now we compare \( p_{3} = 0.50 \) and \( p_{9}=0.48 \). Since \( 0.48<0.50 \), the 9-ounce bottle has a lower unit price.

Answer:

9 - ounce bottle of soap for \$4.32