The perimeter of a rectangular playground is 640 meters, and the ratio of length to width is 5:3. What is the area of the playground in square meters?
一个长方形操场的周长是640米，长与宽的比是5：3．这个操场的面积是多少平方米？
<gadget id="calculator">5 + 3</gadget>
<output>8</output>

<gadget id="calculator">640 / 2 / 8</gadget>
<output>40</output>

<gadget id="calculator">40 * 5</gadget>
<output>200</output>

<gadget id="calculator">640 / 2</gadget>
<output>320</output>

<gadget id="calculator">320 - 200</gadget>
<output>120</output>

<gadget id="calculator">200 * 120</gadget>
<output>24_000</output>

<result>24_000</result>