Answer:
Look at it like this.
For every 2 cups of raisin... 9 cups of trail mix is used
When she uses 12 cups raisin.... How many cups of trail Mix will she use?
The first sentence gives a ratio of 2:9
or 1:9/2
So another interpretation of the sentence... For every 1 cup of raisin... She uses 9/2 cups of trail mix.
Therefore.... when she uses 12 cups of raisins....
She'll have to use
12 x 9/2 cups of trail mix
=54 cups of trail Mix.
ANOTHER APPROACH!
For Every 2cups of raisins... There's 9 cups of trail mix.
When she uses 12 cups of raisins.... There'll be...
2 ----- 9
12 -----x
Cross multiply (in a way)
x = 12 x 9/2
x = 54 cups of trail mix.