Question

Tony is pouring milk for student lunches. She knows that 3 quarts of milk contain 12 cups. How many cups can she pour with 7 quarts of milk? How many quarts will she need to pour 10 cups of milk?

Answer 1

Answer:

7 quarts = 28 cups

10 cups = 2.5 quarts

Step-by-step explanation:

In order to solve the two different questions in the problem, starting with a ratio of the number of quarts to the number of cups would be helpful:

$\frac{quarts}{cups}=\frac{3}{12}=\frac{1}{4}$

So, for every 1 quart of milk, she can pour 4 cups.  Using this ratio, we can set up equivalent ratios, or proportions, to solve for the missing value.  For the first question, we need to know that amount of cups in 7 quarts:

$\frac{1}{4}=\frac{7}{x}$

We can solve for 'x' by multiplying the numerator and denominator by the same factor, in this case '7'.  So, 4 x 7 = 28 cups.

Next, we need to solve for the amount of quarts needed for 10 cups:

$\frac{1}{4}=\frac{x}{10}$

4 x 2.5 = 10, so we need to multiply the numerator by 2.5: 1 x 2.5 = 2.5 quarts.