Ruby and will are running a team relay race. will runs twice as far as ruby. together they run 18 miles. how far did each person run?

First you start thinking of things that add up to 18
9 and 9? no because they would both be equal
so start thinking of thinks that might work, and you will find that 
6+12 is 18!
6= ruby
6x2=will
6x2=12

ruby ran 6 miles and will ran 12.

hope this helps

ruby ran 6 ran 12 because if you add 6 and 12 you get 18