Question

A movie theater put 4 cups of oil for every 9 batches of of popcorn they made. after they had made 45 batches of popcorn, how much oil would they have used?

Answer 1

use ratios 

4:9 = x:45 

what multiplied by 9 = 45 and then multiply that number by 4. 

I'm sure you can figure out the rest by yourself. Good luck and comment if you need further help