The speed ratio of the car and the train is 4:5. They are traveling towards each other from two places at the same time and meet at a place 12 kilometers away from the midpoint. How many kilometers has the train traveled?
汽车与火车的速度比是4：5，它们同时从两地相向而行，在离中点12千米的地方相遇，这时火车走了多少千米？
<gadget id="calculator">4 + 5</gadget>
<output>9</output>

<gadget id="calculator">5 / 9</gadget>
<output>5/9 = around 0.555556</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(5/9) - (1/2)</gadget>
<output>1/18 = around 0.055556</output>

<gadget id="calculator">12 / (1/18)</gadget>
<output>216</output>

<gadget id="calculator">216 * (5/9)</gadget>
<output>120</output>

<result>120</result>