Problem Solving

A necklace is made by stringing N individual beads together in the repeating pattern red bead, green beat, white bead, blue bead, and yellow bead. If the necklace design begins with a read bead and ends with a white bead, then N could equal

A. 16
B. 32
C. 41
D. 54
E. 68

I thought the answer would be D because the sequence is RGWBY and if it begins in R and ends in W, then the number of beads has to be divisible by 3. However, the answer is E. 68...WHY???? Please help!

Thnx.

to solve this just write a simple equation
total no of beads = 5
also note the order R-G-W-B-Y

so if the order starts with R and ends with W the equation will have to be

5X +3 (as W is the 3rd)

so what ever the answer choice - 3 has to be divisible by 5

the only option is 68

as

5X + 3 = 68
5X = 65
X = 13

try the same with choice d and it does not work

Essentially you would want an answer that is divisible by 5 with a remainder of 3.