Question

Will likes two brands of healthy breakfast cereal. In Superfiber cereal, there are 5 grams of fiber in one cup. In Fiber Oats cereal, there are 4 grams of fiber in one cup. Let x represent the number of cups of Superfiber Will ate this week and let y represent the number cups of Fiber Oats he ate this week. Which inequality represents the situation if the cereal Will ate this week contained at least 30 grams of fiber?

a)5x + 4y ≥ 30

b)4x + 5y ≥ 30

c)4x + 5y ≤ 30

Answer 1

Answer: the inequality is: a)5x + 4y ≥ 30

Explanation:

Hi, to solve this problem we have to analyze the information given:

• x : number of cups of Superfiber

• 1 Superfiber cup has 5 grams of fiber ≤ 30

• y: number cups of Fiber Oats

• 1 Fiber Oats cup has 4 grams of fiber

So, the cereal Will ate this week contained at least 30 grams of fiber. At least means more or equal ( ≤ 30 ).

If each cup of Superfiber cup has 5 grams of fiber ⇒ 5x

If each cup of Fiber Oats cup has 4 grams of fiber ⇒ 5y

Finally, the inequality is:

a)5x + 4y ≥ 30

Answer 2

Let x represent the number of cups of Superfiber Will ate this week and let y represent the number cups of Fiber Oats he ate this week.

1. If in Superfiber cereal, there are 5 grams of fiber in one cup, then in x cups there are
`5\cdot x=5x` grams of fiber.

2. If in Fiber Oats cereal, there are 4 grams of fiber in one cup, then in y cups there are
`4\cdot y=4y` grams of fiber.

3. The total amount of fiber Will ate is
`5x+4y` grams.

4. This week Will ate at least 30 grams of fiber. Then

`5x+4y\ge 30.`

Answer: correct choice is A.