Cars A and B start from city A. Car A travels 75 kilometers per hour. After driving for 12 hours, car B chases car A at a speed of 120 kilometers per hour. How long does it take to catch up with car A?
甲、乙两车从A城出发，甲车每小时行75千米，先行12小时后，乙车以每小时120千米的速度去追甲车，多少小时追上甲车？
<gadget id="calculator">120 - 75</gadget>
<output>45</output>

<gadget id="calculator">12 / 45</gadget>
<output>4/15 = around 0.266667</output>

<gadget id="calculator">75 * (4/15)</gadget>
<output>20</output>

<result>20</result>