A recipe that makes 25 oatmeal cookies calls for 2.5 cups of oats and one cup of sugar. Jerry needs

A recipe that makes 25 oatmeal cookies calls for 2.5 cups of oats and one cup of sugar. Jerry needs to make 195 cookies for his school party. How many cups of oats will he need?

Set up a proportion of oats to cookies where c is the number of cups needed to make 195 cookies
2.5/25 = c/195

Using our proportion calculator, we get:
c = 19.5