A grocery store sells four different jars of peanut butter. Determine which is the best​ buy, based on the cost per unit.

Question

14 ounces for ​$1.47 18 ounces for ​$1.82
30 ounces for ​$2.76 40 ounces for ​$4.72

Answer 1

To determine the best buy based on the cost per unit of peanut butter, we need to calculate the cost per ounce for each jar.

1. 14 ounces for $1.47: \[ \text{Cost per ounce} = \frac{1.47}{14} \approx 0.105 \]

2. 18 ounces for $1.82: \[ \text{Cost per ounce} = \frac{1.82}{18} \approx 0.101 \]

3. 30 ounces for $2.76: \[ \text{Cost per ounce} = \frac{2.76}{30} \approx 0.092 \]

4. 40 ounces for $4.72: \[ \text{Cost per ounce} = \frac{4.72}{40} \approx 0.118 \]

Now, let's summarize the cost per ounce for each jar:

• 14 ounces: $0.105 per ounce
• 18 ounces: $0.101 per ounce
• 30 ounces: $0.092 per ounce
• 40 ounces: $0.118 per ounce

Conclusion: The jar with the lowest cost per ounce is the 30 ounces for $2.76, which is approximately $0.092 per ounce. This is the best buy.