A rectangle has a ratio of length to width of 5:3, and its length is 6 cm from its width. What is the perimeter of the rectangle in cm?
一个长方形，长和宽的比是5：3，长比宽长6厘米，这个长方形的周长是多少厘米．
<gadget id="calculator">5 - 3</gadget>
<output>2</output>

<gadget id="calculator">6 / 2</gadget>
<output>3</output>

<gadget id="calculator">3 * 5</gadget>
<output>15</output>

<gadget id="calculator">3 * 3</gadget>
<output>9</output>

<gadget id="calculator">15 + 9</gadget>
<output>24</output>

<gadget id="calculator">24 / 2</gadget>
<output>12</output>

<result>12</result>