A car travels between stations A and B, and the round trip takes 4 hours. It is known that the car travels 45 kilometers per hour when going, and travels 30 kilometers per hour when returning, how many kilometers is the distance between A and B?
一辆汽车在甲、乙两站之间行驶，往返一次共用4小时．已知汽车去时每小时行驶45千米，返回时每小时行驶30千米，求甲、乙两站相距多少千米？
<gadget id="calculator">30 * 4</gadget>
<output>120</output>

<gadget id="calculator">45 + 30</gadget>
<output>75</output>

<gadget id="calculator">120 / 75</gadget>
<output>8/5 = around 1.6</output>

<gadget id="calculator">45 * (8/5)</gadget>
<output>72</output>

<result>72</result>