Questions: Barb is making a bead necklace. She strings 1 white bead, then 3 blue beads, then 1 white bead, and so on. Write the numbers for the first eight beads that are white. What is a rule for the pattern?

Barb is making a bead necklace. She strings 1 white bead, then 3 blue beads, then 1 white bead, and so on. Write the numbers for the first eight beads that are white. What is a rule for the pattern?
Transcript text: Barb is making a bead necklace. She strings 1 white bead, then 3 blue beads, then 1 white bead, and so on. Write the numbers for the first eight beads that are white. What is a rule for the pattern?
failed

Solution

failed
failed

Solution Steps

Step 1: Analyze the pattern

Barb strings beads in the following repeating sequence: 1 white bead, followed by 3 blue beads. This pattern repeats continuously. The sequence of beads can be represented as: \[ \text{White}, \text{Blue}, \text{Blue}, \text{Blue}, \text{White}, \text{Blue}, \text{Blue}, \text{Blue}, \dots \]

Step 2: Identify the positions of white beads

The white beads appear at the beginning of each repetition of the pattern. The positions of the first eight white beads are:

  1. Position 1 (1st bead)
  2. Position 5 (5th bead)
  3. Position 9 (9th bead)
  4. Position 13 (13th bead)
  5. Position 17 (17th bead)
  6. Position 21 (21st bead)
  7. Position 25 (25th bead)
  8. Position 29 (29th bead)
Step 3: Derive the rule for the pattern

The positions of the white beads follow an arithmetic sequence where each white bead is 4 positions apart. The rule for the \(n\)-th white bead's position is: \[ \text{Position of } n\text{-th white bead} = 4n - 3 \]

Final Answer

The positions of the first eight white beads are: \[ \boxed{1, 5, 9, 13, 17, 21, 25, 29} \] The rule for the pattern is: \[ \boxed{\text{Position of } n\text{-th white bead} = 4n - 3} \]

Was this solution helpful?
failed
Unhelpful
failed
Helpful