Martha is flying to England for a visit. She intends to exchange her U.S. dollars for English pounds. The exchange rate allows 60 pounds for every 100 U.S. dollars. How many pounds will she get if she exchanges $450 U.S. dollars for pounds?
60:x = 100:450 ( this is how I was trying to work this out but again, I don't the answer in my book ).
Help greatly appreciated.
Thanks
Your ratio is wrong. Put the pounds on top and the dollars on the bottom. Or you could reverse that.
60/100 = x/450
Cross multiply and solve for x.
100x = 27,000
x = 270 pounds
The book I am learning from gives an answer of 750 pounds. I am working out of Mathematics Made Simple fifth edition. It doesn't show the work. It shows me one way of doing certain problems and then changes. frusterating? Thank you for your help.
Either you've copied the problem wrong, or your book's answer is wrong.
The problem states that you for 60 pounds, you pay $100. Therefore you'll get a smaller number of pounds than dollars.
Look at it this way.
Pay $100; get 60 pounds
Pay $200; get 120 pounds
Pay $300; get 180 pounds
Pay $400; get 220 pounds
To find out how many pounds Martha will get if she exchanges $450 U.S. dollars for pounds, we can use a proportion based on the given exchange rate:
Exchange rate: 60 pounds for every 100 U.S. dollars
Let's set up the proportion using the x as the unknown number of pounds she will get:
60 pounds / 100 U.S. dollars = x pounds / $450 U.S. dollars
To solve for x, we cross-multiply:
(60 pounds * $450 U.S. dollars) = (100 U.S. dollars * x pounds)
27,000 pounds = 100 U.S. dollars * x pounds
Now we can divide both sides by 100 U.S. dollars to solve for x:
27,000 pounds / 100 U.S. dollars = x pounds
x = 270 pounds
Therefore, if Martha exchanges $450 U.S. dollars, she will get 270 pounds.