http://web2.0calc.com/questions/your-teacher-asks-you-to-find-a-recipe-that-includes-two-ingredients-with-a-rate-of-2-units-over-3-units I have no idea what

Try this: 

There are various recipes that use a ratio of one item to another as the rate of 2 : 3.

For instance, for chicken casserole, a recipe may tell you to use 2 cups of cooked rice to 3 cups of cooked (diced) chicken.

Thank you, just the word "rate" was confusing.