The passenger car and the truck are traveling towards each other from two places 2160 kilometers apart at the same time. The passenger car travels 80 kilometers per hour, and the speed of the truck per hour is (4/5) that of the passenger car. After how many hours did the two cars meet?
客车和货车同时从相距2160千米的两地相向而行，客车每小时行80千米，货车每小时的速度是客车的(4/5)．经过多少小时两车相遇？
<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">80 * (4/5)</gadget>
<output>64</output>

<gadget id="calculator">80 + 64</gadget>
<output>144</output>

<gadget id="calculator">2_160 / 144</gadget>
<output>15</output>

<result>15</result>