The Best Buy

By: Jordyn Coffin

Question

A pack of 24 styrofoam cups cost $1.25 and the total with tax is $2.28.

A pack of 36 styrofoam cups cost $1.85 and the total with tax is $3.37.

Which is the better buy?

Proportion

24 36

---- - -----

1.25 1.85

Solving

To solve I will turn both proportions into unit rates by dividing the number of cups to the total price to see how much money 1 cup would cost.


1.25 / 24 = 5.2 cents

1.85 / 36 = 5.1 cents

Why is the unit rate helpful?

It is helpful to turn it into a unit rate because that's what helps you to know what 1 item would cost and the one that cost less would be the item whose whole price cost less.
Knowing the unit rate showed us that he 36 pack of cups is a better price so you should buy that one.