To find a percent, you need to put the numbers into a fraction first. Since the total number of beads is there, that is the denominator (number on the bottom of the fraction). The purple bead number will go on the top. This makes the fraction 8/12. When you divide 12 by 8, you get the decimal 0.66666667. You move the decimal two places over and get ~66%. This makes your answer B. Hope this helps! :)