It takes Xiaofang 12 seconds to walk from the first floor to the third floor. At this speed, how many seconds does it take her to go from the third floor to the seventh floor?
小芳从一楼走到三楼用12秒钟，按这样的速度，她从三楼到七楼要多少秒钟．
<gadget id="calculator">3 - 1</gadget>
<output>2</output>

<gadget id="calculator">12 / 2</gadget>
<output>6</output>

<gadget id="calculator">7 - 3</gadget>
<output>4</output>

<gadget id="calculator">6 * 4</gadget>
<output>24</output>

<result>24</result>