Ratios and Proportions

A recipe for pasta noodles calls for 3 large eggs (3/4 cup), 2 cups of flour, 2 teaspoons of salt and 1 tablespoon of olive oil. This makes 4 servings of pasta noodles. Convert this recipe to one that would make 10 servings.

Solution: 1.875 cups of eggs, 5 cups flour, 5 teaspoons of salt and 2.5 tablespoons of oil

Sketch:

Building ratios for number of servings to each ingredient gives:

servings : eggs =  4 : .75
servings : flour = 4 : 2  
servings : salt =  4 : 2  
servings : oil =   4 : 1

To find the amount of eggs for 10 servings we solve the proportion

4 : .75 = 10 : x,

which gives x = 1.875 cups of eggs.

The other ingredients are done the same way, giving: 5 cups flour, 5 teaspoons of salt and 2.5 tablespoons of oil.

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Solution: 1.875 cups of eggs, 5 cups flour, 5 teaspoons of salt and 2.5 tablespoons of oil Sketch:

Solution: 1.875 cups of eggs, 5 cups flour, 5 teaspoons of salt and 2.5 tablespoons of oil

Sketch: