The radius of the driving wheel of the train is 75 centimeters. If it turns 300 times per minute, how many meters can it do per hour?
火车主动轮的半径是75厘米，如果每分钟转300周，每小时可行多少米？
<gadget id="calculator">75 / 100</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">(3/4) * 2</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">3.14 * (3/2) * 300 * 1 * 60</gadget>
<output>84_780</output>

<result>84_780</result>