Question

Mayonnaise comes in 32-, 16-, and 8-oz jars. They are priced at $5.59, $3.79, and $2.59, respectively. Find theunit cost of each size jar to find the best buy. (Round to three decimal places.)

Answer 1

The values for the three jars are,

$\begin{gathered} 32-\text{oz jars,} \\ 16-oz\text{ jars,} \\ 8-oz\text{ jars} \end{gathered}$

Their costs are written below respectively,

$\begin{gathered} \text{ \ 5.59} \\ \text{ \ }3.79 \\ \text{ \ }2.59 \end{gathered}$

To calculate for the unit costs, we divide each cost by the amount of jars.

For the 32-oz jars,

$\begin{gathered} if\text{ 32-oz jars=\ 5.59} \\ \text{Then, the cost of \ 1 will be} \\ \text{ 1-oz jar=}\frac{\text{\ 5.59}}{32}=\text{ \ 0.174687}\approx\text{ \ 0.175(nearest 3decimal places)} \\ \therefore\text{ 1-oz jar}=\text{\ 0.175} \end{gathered}$

For the 16-oz jars,

$\begin{gathered} \text{if 16-oz jars=\ 3.79} \\ 1-oz\text{ jar=}\frac{\text{\ 3.79}}{16}=\text{ \ 0.236875}\approx\text{ \ 0.237(nearest 3 decimal places)} \\ \therefore1-oz\text{ jar}=\text{\ 0.237} \end{gathered}$

For the 8-oz jars,

$\begin{gathered} \text{if 8-oz jars=\ 2.59} \\ 1-oz\text{ jar=}\frac{\text{\ 2.59}}{8}=\text{ \ 0.32375}\approx\text{ \ 0.324(nearest 3 decimal places)} \\ \therefore1-oz\text{ jar}=\text{\ 0.324} \end{gathered}$

To check for the best buy, it will be the one that gives the least unit cost.

From the calculations of the unit cost of the jars done, we could see that 32-oz jars gave us the least cost price.

Hence, the best buy is 32-oz jars which gave us $0.175 unit cost.