Question

The recommended daily calcium intake for a 20-year-old is 1,000 milligrams (mg). One cup of milk contains 299 mg of calcium and one cup of juice contains 261 mg of calcium. Which of the following inequalities represents the possible number of cups of milk m and cups of juice j a 20-year-old could drink in a day to meet or exceed the recommended daily calcium intake from these drinks alone?

Answer 1

One possible inequality is:

299m+261j ≥ 1000.

Explanation:

m is the number of cups of milk and j is the number of cups of juice.

Each cup of milk contains 299 mg of calcium.  This gives us 299m mg of calcium for m cups of milk drank.

Each cup of juice contains 261 mg of calcium.  This gives us 261j mg of calcium for j cups of juice drank.

Together, this would be a total of 299m+261j mg of calcium.

We want to meet or exceed 1000 mg of calcium.  This means we could have more than 1000 or equal to 1000; this gives us the inequality symbol "greater than or equal to":

299m+261j ≥ 1000