Two fast and slow trains depart from A and B oppositely at the same time, and meet each other after 20 hours. It is known that the slow train will take 60 hours to complete the journey. When they meet, what fraction of the entire journey will the express train travel?
快慢两列车同时从甲、乙两城相对开出，经20小时相遇，已知慢车行完全程要60小时，相遇时，快车行了全程的几分之几？
<gadget id="calculator">1 / 20</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">1 / 60</gadget>
<output>1/60 = around 0.016667</output>

<gadget id="calculator">(1/20) - (1/60)</gadget>
<output>1/30 = around 0.033333</output>

<gadget id="calculator">(1/30) * 20</gadget>
<output>2/3 = around 0.666667</output>

<result>2/3 = around 0.666667</result>