MathDB
SMT 2010 General #9

Source:

February 11, 2012
geometric series

Problem Statement

A straight line connects City A at (0,0)(0, 0) to City B, 300 meters away at (300,0)(300, 0). At time t=0t=0, a bullet train instantaneously sets out from City A to City B while another bullet train simultaneously leaves from City B to City A going on the same train track. Both trains are traveling at a constant speed of 5050 meters/second.
Also, at t=0t=0, a super y stationed at (150,0)(150, 0) and restricted to move only on the train tracks travels towards City B. The y always travels at 60 meters/second, and any time it hits a train, it instantaneously reverses its direction and travels at the same speed. At the moment the trains collide, what is the total distance that the y will have traveled? Assume each train is a point and that the trains travel at their same respective velocities before and after collisions with the y