QuestionNoemi strings together green beads at each with 3 blue beads at each. She makes a bracelet that averages per bead. Choose an equation to model the situation. A. B. C. D.
Studdy Solution
STEP 1
What is this asking?
How many green beads does Noemi need to make the average cost of the bracelet per bead?
Watch out!
Don't forget to include the cost of *both* the green *and* blue beads!
Also, the average cost is per bead, so we need to consider the *total* number of beads.
STEP 2
1. Define the total cost of green beads.
2. Define the total cost of blue beads.
3. Define the total cost of all beads.
4. Define the total number of beads.
5. Define the average cost per bead.
6. Set up the equation.
7. Solve for .
STEP 3
Noemi uses green beads, and each one costs .
So, the **total cost** of the green beads is .
Easy peasy!
STEP 4
She uses **3** blue beads at each.
So, the **total cost** of the blue beads is .
STEP 5
To get the total cost of *all* the beads, we just **add** the cost of the green beads and the cost of the blue beads: .
STEP 6
There are green beads and **3** blue beads.
That means there are a total of beads.
STEP 7
The problem tells us the average cost per bead is .
We also know the total number of beads is .
So, the **total cost** of all the beads can *also* be written as .
STEP 8
Now, we have *two* ways to express the total cost of the beads: and .
Since both represent the same thing, we can set them equal to each other!
Our equation is .
STEP 9
Although the problem doesn't ask us to solve, let's do it anyway for extra practice! **Distribute** the on the right side: .
STEP 10
**Subtract** from both sides: .
STEP 11
**Subtract** from both sides: .
STEP 12
**Divide** both sides by : .
So, Noemi needs **6** green beads!
STEP 13
The equation that models the situation is C. .
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