Take a train from A to B, travel 120 kilometers per hour, and arrive in 6 hours. From January 2007, the speed will be increased to 180 kilometers per hour. How many hours can you arrive after the speed increase?
乘火车从甲地到乙地，每小时行120千米，6小时到达，从2007年元月开始将每小时提速到180千米，提速后几小时可以到达？
<gadget id="calculator">6 / 180</gadget>
<output>1/30 = around 0.033333</output>

<gadget id="calculator">120 * (1/30)</gadget>
<output>4</output>

<result>4</result>