C. Interpret, Compare, and Convert Rates

Rates can be used to solve a variety of problems.

You may be familiar with the phrase 'comparing apples to apples'. Unit rates allow us to do just that. Determining which offer is the better buy is a common consumer problem that can be solved by comparing unit rates (apples to apples).

Example 1

Which is the better buy: 5 used games for $62.29 or 4 used games for $51.89?

The unit is 1 game.

or $12.46/game

or $12.97/game

The better buy is the 5 used games.

A currency exchange rate is the measure of the value of one currency compared to the value of another currency. Currency conversion is required when you travel from one country to another because each country has its own currency and in many cases will not accept the currency of other countries.

Example 2

The April 2013 exchange rate for one Canadian dollar in British pounds is 1.00 CAD = £0.64.

Determine the value of $150.00 Canadian in British pounds.

Let x = unknown value in British pounds.

Convert the Canadian funds to British pounds.

150.00 CAD was worth £96.00 in April 2013.