Measured on a plan with a scale of 1:500, the perimeter of a rectangular classroom is 10 cm, and the ratio of length to width is 3:2. What is the actual size of this classroom?
在一幅比例尺为1：500的平面图上量得一间长方形教室的周长是10厘米，长与宽的比是3：2．这间教室的实际面积是多大？
<gadget id="calculator">2 + 3</gadget>
<output>5</output>

<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">1 / 500</gadget>
<output>1/500 = around 0.002</output>

<gadget id="calculator">(3/5) / (1/500) / 100</gadget>
<output>3</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">(2/5) / (1/500) / 100</gadget>
<output>2</output>

<gadget id="calculator">5 * 3 * 5 * 2</gadget>
<output>150</output>

<result>150</result>