The big customs bell rings once at 1 o'clock and twice at 2 o'clock... At 6 o'clock, Xiaohong heard the clock ringing for 30 seconds, so how many seconds does it take to ring the bell at 12 o'clock?
海关大钟，1点钟敲一下，2点钟敲两下…6点钟时，小红听到钟共敲了30秒，那么12点钟敲钟的时间共需要多少秒．
<gadget id="calculator">12 - 1</gadget>
<output>11</output>

<gadget id="calculator">30 / 5</gadget>
<output>6</output>

<gadget id="calculator">11 * 6</gadget>
<output>66</output>

<result>66</result>