Center of Mass

$M=100\text{g}, m=10\text{g}, v_{bead}=11\text{cm/s}$.

Velocity of CM: $V_{cm} = \frac{10(11) + 100(0)}{110} = 1 \text{ cm/s}$.

In 60s, CM travels $60 \text{ cm}$.

Bead Position

Bead travels 11 cm/s. Length 22 cm. Time to cross = 2s.

Starts at center. Hits wall at 1s, 3s, 5s…

At $t=60\text{s}$, it is at the midpoint (same as start relative to box).

Therefore, displacement of Box = Displacement of CM = 60 cm.