苏珊（Susan）总共有 117 个珠子和弹珠。这些珠子和弹珠要么是白色的，要么是黑色的。20% 的珠子和 50% 的弹珠是白色的。黑珠子的数量和黑弹珠的数量一样多。

1. Find the percentage of black beads and black marbles.

Percentage of black beads = $100\% - 20\% = 80\%$
Percentage of black marbles = $100\% - 50\% = 50\%$

2. Equate the fractions of black beads and black marbles to find the ratio of total beads to total marbles.

Since the number of black beads equals the number of black marbles:
$80\%$ of beads = $50\%$ of marbles
$\frac{4}{5}$ of beads = $\frac{1}{2}$ of marbles
$\frac{4}{5}$ of beads = $\frac{4}{8}$ of marbles
Ratio of beads to marbles = $5 : 8$

3. Compare the number of units to determine the relationship.

Since $5$ units $< 8$ units, the number of beads is fewer than the number of marbles.