A recipe calls for 3 cups of milk to accommodate 8 people. However, you are preparing food for 20 people. What are the number of cups of milk you will need for 20 people?

Use a proportion to solve.

The original recipe is 3 cups for 8 people, which can be written as a proportion of 3/8

You want to make enough for 20 people, let X be the number of cups required, so the proportion for this would be x/20.

Now you have two proportions, set them to equal:

3/8 = x/20

Cross multiply:

(3*20) = (8*x)

Simplify"

60=8x

Divide both sides by 8:

x = 60/8

x = 7.5

You will need 7.5 cups (7 1/2 as a fraction)