Let x be the speed of the bus, in miles per hour. Then the speed of the train is (x+42) miles per hour. Then you write this "distance" equation 5x = 2*(x + 42) saying that the distance is the same. Simplify and solve 5x = 2x + 84 5x - 2x = 84 3x = 84 x = 84/3 = 28. ANSWER. The bus speed is 28 miles per hour.