A train travels from A to B at 120 kilometers per hour, and 70% of the journey is left in 2 hours. How many kilometers is the total length from A to B?
一列火车从甲地开往乙地，每小时行120千米，行驶2小时还剩全程的70%，甲地到乙地全长多少千米？
<gadget id="calculator">120 * 2</gadget>
<output>240</output>

<gadget id="calculator">70 / 100</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">1 - (7/10)</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">240 / (3/10)</gadget>
<output>800</output>

<result>800</result>