There is a rectangular lawn that is 5 meters wide and twice as long as it is wide, what is its perimeter in meters?
有一块长方形草坪，宽是5米，长是宽的2倍，它的周长是多少米？
<gadget id="calculator">5 * 2</gadget>
<output>10</output>

<gadget id="calculator">10 + 5</gadget>
<output>15</output>

<gadget id="calculator">15 * 2</gadget>
<output>30</output>

<result>30</result>