Two gliders, (X and Y), collided on a horizontal, frictionless air-track. Due to the velcro strips attached to each glider, they stuck together after the collision. The mass of glider X was $0.15\text{ kg}$ and its velocity before the collision was $0.27\text{ m/s}$ to the right (the positive direction). The mass of glider Y was $0.25\text{ kg}$ and its velocity before the collision was $0.19\text{ m/s}$ to the left.

Which of the following values was the velocity of the center of mass of the two glider system before the collision?