The perimeter of a rectangle is 60 decimeters, and the ratio of length to width is 3:2. What is the length of the rectangle?
一个长方形的周长是60分米，长与宽的比是3：2，这个长方形的长是多少．
<gadget id="calculator">3 + 2</gadget>
<output>5</output>

<gadget id="calculator">60 / 2 / 5</gadget>
<output>6</output>

<gadget id="calculator">6 * 3</gadget>
<output>18</output>

<result>18</result>