An airplane can fly for up to 5 hours with the fuel it carries. When flying out, it can fly 1,500 kilometers per hour with the wind, and when it returns, it can fly 1,000 kilometers per hour against the wind.
一种飞机所带的燃料最多可飞行5小时，飞出时顺风第小时飞行1500千米，返回时逆风每小时飞行1000千米，这架飞机最多能飞出多少千米就应往回飞．
<gadget id="calculator">1 / 1_500</gadget>
<output>1/1_500 = around 0.000667</output>

<gadget id="calculator">1 / 1_000</gadget>
<output>1/1_000 = around 0.001</output>

<gadget id="calculator">(1/1_500) + (1/1_000)</gadget>
<output>1/600 = around 0.001667</output>

<gadget id="calculator">5 / (1/600)</gadget>
<output>3_000</output>

<result>3_000</result>