Draw a rectangular lawn with a ratio of length to width of 5:3 on the drawing with a scale of (1/400), and the perimeter of the rectangle obtained is 24 cm. What is the actual area of this rectangular lawn in square meters?
把一块长与宽的比为5：3的长方形草坪，用(1/400)的比例尺画在图纸上，得到的长方形的周长是24厘米．这块长方形草坪的实际面积是多少平方米？
<gadget id="calculator">24 / 2</gadget>
<output>12</output>

<gadget id="calculator">5 + 3</gadget>
<output>8</output>

<gadget id="calculator">3 / 8</gadget>
<output>3/8 = around 0.375</output>

<gadget id="calculator">12 * (3/8)</gadget>
<output>9/2 = around 4.5</output>

<gadget id="calculator">12 - (9/2)</gadget>
<output>15/2 = around 7.5</output>

<gadget id="calculator">1 / 400</gadget>
<output>1/400 = around 0.0025</output>

<gadget id="calculator">(15/2) / (1/400) / 100</gadget>
<output>30</output>

<gadget id="calculator">(9/2) / (1/400) / 100</gadget>
<output>18</output>

<gadget id="calculator">30 * 18</gadget>
<output>540</output>

<result>540</result>