need 1/3 cup of sauce for a recipe, but john only has 1/4 of a cup. how much of the recipe can he make?

Question

john's recipe will produce many servings, and calls for 1/3 of a cup of sauce. john only has 1/4 of a cup of sauce, so he can't make the whole batch. assuming he has enough of all other ingredients, what fraction of the recipe can john make?

Answer 1

We need to set up a ratio

 

What is the ratio of 1/4 to 1/3?

 

1/4 : 1/3 = 1/4 ÷ 1/3 = 1/4 * 3 = 3/4, so John can make 3/4 of the recipe

 

We can check this also by finding a common denominator for the two fractions

 

1/3 = 4/12, and 1/4 = 3/12

 

If the whole recipe calls for 1/3 or 4/12 of a cup of sauce, then 1/4 of the recipe would call for 1/4 * 1/3 = 1/12 of the recipe. 

 

If 1/4 of the recipe calls for 1/12 cups of sauce, then 3/4 of the recipe would call for:

 

3 * (1/12) = 3/12 = 1/4, which is how much sauce John has