Question

A company sells cereal in two different-sized boxes: a 17-ounce box for $2.89, and a 24-ounce box for $3.29. How do the unit prices of the two boxes compare?
The smaller box is the better buy because it is approximately 1.4 cents cheaper per ounce.
The smaller box is the better buy because it is approximately 3.3 cents cheaper per ounce.
The larger box is the better buy because it is approximately 1.4 cents cheaper per ounce.
The larger box is the better buy because it is approximately 3.3 cents cheaper per ounce.

Answer 1

Answer: Last option.

Step-by-step explanation:

Let be "s" the unit price of the smaller box and "l"  the unit price of the larger box.

According to the information given in the exercise, the smaller one is a 17-ounce box which costs $2.89. Therefore, in order to find the value of "s", you need to divide  $2.89 by 17 ounces. This is:

$s=\frac{2.89\ dollars}{17\ ounce}\\\\s=0.17\ \frac{dollars}{ounce}$

You know that the larger box has 24 ounces and it costs $3.29.

Therefore, in order to find the value of "l", you need to divide  $3.29 by 24 ounces. This is:

$l=\frac{3.29\ dollars}{24\ ounce}\\\\l=0.137\ \frac{dollars}{ounce}$

Finally, find the difference:

$0.17\ \frac{dollars}{ounce}-0.137\ \frac{dollars}{ounce}=0.033\ \frac{dollars}{ounce}$ or $3.3\ \frac{cents}{ounce}$

Therefore, you can conclude that the larger box is better buy because it is approximately 3.3 cents cheaper per ounce.