Bicycle tires can travel 5,000 kilometers on the front wheels, and only 3,000 kilometers on the rear wheels. When the bicycle travels a certain distance, the front and rear tires can be exchanged to improve the utilization rate of the tires. How many kilometers can a pair of such tires travel at most?
自行车轮胎，装在前轮上可行驶5000千米，装在后轮上只能行驶3000千米，当自行车行驶一定路程后，前后轮胎交换位置，可以提高轮胎的利用率．问一对这样的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>