The distance between A and B is 494 kilometers. A truck drives from point A to point B at a speed of 60 km/h. After 2 hours, a bus drives from point B to point A. After another 3.4 hours, the two vehicles meet. What is the speed of the bus?
甲乙两地相距494千米．货车以60千米/时的速度从甲地开往乙地，2小时后，客车才从乙地开往甲地，再经过3.4小时两车相遇，客车的速度是多少？
<gadget id="calculator">60 * 2</gadget>
<output>120</output>

<gadget id="calculator">60 * 3.4</gadget>
<output>204</output>

<gadget id="calculator">494 - 120 - 204</gadget>
<output>170</output>

<gadget id="calculator">170 / 3.4</gadget>
<output>50</output>

<result>50</result>