Sally has a recipe that needs 1 1/2 tsp. of butter for every3 cups of milk. If Sally increases the amount of milk to 13 1/2 cups of milk, how many tsp. of butter are needed?
1.5/3 = x/13.5
Cross multiply and solve for x.
To find out how many teaspoons of butter are needed when Sally increases the amount of milk, we can use a proportion.
We know that 1 1/2 teaspoons of butter is needed for every 3 cups of milk. So the ratio of teaspoons of butter to cups of milk is 1 1/2 : 3.
We can set up a proportion:
(1 1/2 tsp) / (3 cups) = x tsp / (13 1/2 cups)
To solve this proportion, we can cross multiply:
(1 1/2 tsp) * (13 1/2 cups) = (3 cups) * (x tsp)
To simplify the left side, we need to convert the mixed numbers to improper fractions:
(3/2 tsp) * (27/2 cups) = (3 cups) * (x tsp)
Now, we can cancel out the common factors:
(3/1 tsp) * (9/1 cups) = (1 cup) * (x tsp)
Multiplying the numerators gives us:
27/1 tsp = x tsp
Therefore, when Sally increases the amount of milk to 13 1/2 cups, she will need 27 teaspoons of butter.