Since there are a total of 48 beads and each bead will either be blue or yellow, in order to find out how many of each colour bead she will use, do the following:
Divide 48 by 3 to get 16 yellow beads.
Now that you know how many yellow beads there are, just subtract that from 48:
48 - 16 = 32
Therefore, she will use 16 yellow beads and 32 blue beads.
