If the bicycle tire is installed on the front wheel, it will be scrapped after driving 5000 kilometers; if it is installed on the rear wheel, it can only travel 3000 meters. In order to travel as much as possible, if the method of changing the front and rear tires is adopted when the bicycle travels a certain distance, how many kilometers can a pair of tires installed on the bicycle travel at most?
自行车轮胎安装在前轮上，行驶5000千米报废；若安装在后轮上，只能行驶3000米．为了行驶尽可能多的路，如果采用当自行车行驶一定路程时前后轮胎调换的方法，那么安装在自行车上的一对轮胎，最多可以行驶多少千米？
<gadget id="calculator">1 + 1</gadget>
<output>2</output>

<gadget id="calculator">1 / 5_000</gadget>
<output>1/5_000 = around 0.0002</output>

<gadget id="calculator">1 / 3_000</gadget>
<output>1/3_000 = around 0.000333</output>

<gadget id="calculator">(1/5_000) + (1/3_000)</gadget>
<output>1/1_875 = around 0.000533</output>

<gadget id="calculator">2 / (1/1_875)</gadget>
<output>3_750</output>

<result>3_750</result>