Question

Barb is making a bead necklace. She strings on 1 white bead, then three blue beads, then one white bead and so on write the number for the first eight beads that are white. What is the rule for the pattern?

Answer 1

Answer:

The serial numbers of first 8 white beads are = 1, 5, 9, 13, 17, 21, 25, 29,

Step-by-step explanation: Since there are 3 blue beads after each white beads, Hence we can design the progression in the following way looking at the sequence:

W,B,B,B,W,B,B,B,W.......

Hence the required formula for white beads serial number is,

N = (X-1)(A+1) + L

Where, A = number of blue beads after each white beads = 3

L = initial position at which the first white bead is placed = 1

X = number of white bead

Putting the values in the above formula our equation becomes,

N = 4(X-1) + 1

Hence we can find out the serial numbers as follows:

N₁ = 4 x 0 + 1 = 1

N₂ = 4x1 + 1 = 5

N₃ = 4x2 + 1 = 9

and so on upto

N₈ = 4 x 7 + 1 = 29