Awarding 100 points for immediate answer.

Two tectonic plates, Plate X and Plate Y, are moving towards each other. Plate X is moving at a speed of 4 centimeters per year, while Plate Y is moving at a speed of 6 centimeters per year. If the distance between the plates is currently 150 kilometers, how long will it take for the plates to collide?

2000 years
2500 years
1500 years
1250 years