From A to B, A needs to walk for 2 hours, and B needs to walk for 1 hour and 40 minutes. If A starts from A 8 minutes later, B starts from A to chase A. How long does it take for B to catch up with A?
从A地到B地，甲要走2小时，乙要走1小时40分钟．若甲从A地出发8分钟后，乙从A地出发追甲．乙出发多久能追上甲？
<gadget id="calculator">1 / 120</gadget>
<output>1/120 = around 0.008333</output>

<gadget id="calculator">1 / 100</gadget>
<output>1/100 = around 0.01</output>

<gadget id="calculator">(1/100) - (1/120)</gadget>
<output>1/600 = around 0.001667</output>

<gadget id="calculator">8 / (1/600)</gadget>
<output>4_800</output>

<gadget id="calculator">(1/120) * 4_800</gadget>
<output>40</output>

<result>40</result>