Two trains A and B depart from two places 600 kilometers apart at the same time. Train A travels 80 kilometers per hour. After 2.4 hours, the distance between the two trains is still the full distance (2/5). How many kilometers per hour does train B travel?
甲乙两列火车从相距600千米的两地同时相对开出，甲车每小时行80千米，2.4小时后两车还相距全程的(2/5)，乙车每小时行多少千米？
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (2/5)</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">(3/5) / 2.4</gadget>
<output>0.25</output>

<gadget id="calculator">600 * 0.25</gadget>
<output>150</output>

<gadget id="calculator">150 - 80</gadget>
<output>70</output>

<result>70</result>