It takes 8 seconds for the clock on the square to strike 5 times at 5 o'clock. How many seconds does it take to knock 10 times at 10 o'clock?
广场上的钟5时敲5下需要8秒钟敲完．10时敲10下需要多少秒钟敲完．
<gadget id="calculator">10 - 1</gadget>
<output>9</output>

<gadget id="calculator">5 - 1</gadget>
<output>4</output>

<gadget id="calculator">8 / 4</gadget>
<output>2</output>

<gadget id="calculator">9 * 2</gadget>
<output>18</output>

<result>18</result>