Uncle Zhang drove from City A to City B to deliver goods. He drove for 3 hours at a speed of 30 m/h and arrived in only 2 hours. How many kilometers does Uncle Zhang travel from City A to City B in one round trip on average per hour? ?
张叔叔从甲城开车送货到乙城，以30米/时的速度行驶了3小时到达，返回时只用了2小时，张叔叔从甲城到乙城往返一次平均每小时行驶多少千米？
<gadget id="calculator">30 * 3 * 2</gadget>
<output>180</output>

<gadget id="calculator">3 + 2</gadget>
<output>5</output>

<gadget id="calculator">180 / 5</gadget>
<output>36</output>

<result>36</result>