Everyday Unit Rates 3

Many people in the Lower Mainland cross over the border to shop in Blaine or Bellingham, because the prices are considerably cheaper on many items.  One of the most shopped-for items is gasoline, where hundreds of people visit Whatcom County just to fill up with gasoline for much less than they can in Langley or Abbotsford.  But how much cheaper is it?  They use a gallon and we use a litre to measure liquid volume.  And even though we both use "dollars" for currency, they are worth different values and an exchange is used to determine the relationship.

By using some simple proportion problems we can calculate just how much is saved by filling up in the US.

For example, if 1 US gallon (USG) equals 3.79 litres (L), how many litres would 15.872 USG equal?  This can be solved by using a proportion problem (like we used in class).

If my bank used an exchange rate of 1.0570, where 1 USD = 1.0570 CDN, how much did $58.71 USD equal in Canadian dollars?  (round your answer to the nearest cent)

How much would this same volume of gasoline cost in Canada?  To find out, multiply the number of litres (figured out earlier) by the local price (say, $1.349 CDN).  You can then figure out how much was saved by crossing the border to fill up.