Question

John bought oat milk and whole milk for a total of $280. The oat milk costs $20 per ounce, and the whole milk costs $60 per ounce. Moreover, John bought 2 more ounces of oat milk than whole milk. How many ounces of oat milk did John purchase?

Answer 1

5 ounces

Explanation:

Pre-Solving

We know that John bought some ounces of oat milk for $20/ounce and some ounces of whole milk for $60/ounce, and the total was $280.

We also know that John bought 2 more ounces of oat milk than whole milk.

This means that if John bought x ounces of oat milk, he must have bought x-2 ounces of whole milk.

So this means the total amount of oat milk that John bought is 20x dollars, and the total amount of whole milk bought is 60(x-2).

Solving

We can create an equation out of this.

Since the total amount of oat + whole milk bought is 280:

20x + 60(x-2) = 280

Do the distributive property.

20x + 60x - 120 = 280

Add the like terms together.

80x - 120 = 280

Add 120 to both sides.

80x = 400

Divide both sides by 80.

x = 5

Since x is the amount of oat milk ounces that John bought, that means 5 ounces of oat milk were bought.