If the perimeter of a rectangle is 20 cm and the ratio of length to width is 3:2, what is the length of the rectangle in cm?
长方形的周长是20厘米，长与宽的比是3：2，长方形的长是多少厘米．
<gadget id="calculator">20 / 2</gadget>
<output>10</output>

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

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

<gadget id="calculator">10 * (3/5)</gadget>
<output>6</output>

<result>6</result>