Answer:
The answer to your question is: 75%.
Step-by-step explanation:
Data
Necklace has 36 blue beads
            12 white beads
Total number of beads = 48
Process
Use a rule of three
                 48 beads ------------------- 100 %
                 36 beads -------------------  x
                 x = (36 x 100) / 48
                 x = 3600 / 48
                 x = 75 % are blue beads